The spring constant for a spring with load of 80 N and which extends by 12 cm is -333.34 N/m for each springs.
What is spring constant?
According to Hooke's Law, when a spring is stretched, the force applied is proportional to the lengthening from the equilibrium length. The formula k = -F/x, where k is the spring constant, can be used to get the spring constant. F stands for force, and x for the variation in spring length.
The spring constant is calculated by dividing the force required to stretch or compress a spring by the lengthening or shortening of the spring. It is used to identify whether a spring is stable or unstable, and consequently, what system it should be employed in.
According to Hooke's law
k = -F/x
Where, k = spring constant
F = force,
x = variation in spring.
As given in the question,
There are two springs which support 80 N force so one will support 40 N
F = 40 N, x = 12 cm, k needs to be found out
putting the values in Hooke's law,
we get, k = -333.34 N/m
Therefore, the spring constant here is -333.34 N/m for each springs
To know more about spring constant, go to link
https://brainly.com/question/23885190
#SPJ9
a hydraulic lift requires a minimum effort force of 14.4N to lift a patient of a mass 82kg .How much is the effort piston area if the resistance piston has an area of 1.2m²
The output force of a hydraulic lift is given by:
[tex]F_2=\frac{A_2}{A_1}F_1[/tex]In this case we need to lift a patient of mass 82 kg, that means that the lifting force has to be equal to:
[tex]F_2=82\cdot9.8=803.6[/tex]Now that we know that we plug the values given, in this case we have:
[tex]\begin{gathered} 803.6=\frac{1.2}{A_1}(14.4) \\ A_1=\frac{1.2}{803.6}(14.4) \\ A_1=0.022 \end{gathered}[/tex]Therefore the area of the effort piston is 0.022 squared meters (rounded to three decimal).
what happens to the temperature of the car brake when a driver brake decelerate quickly
Answer:
This reduces the kinetic energy of the vehicle, slowing it down and causing the temperature of the brakes to increase. Decelerating from very high speeds too quickly can cause a number of problems: The brakes could overheat and the material they are made from could shatter.
7 The distance-time graph for a motorcyclist riding off from rest is shown in Figure 1.2.18.
a Describe the motion.
b Calculate how far the motorbike moves in 30 seconds.
c Calculate the speed.
The distance travelled by the motorbike is 600 m and the speed of the motorbike is 20 m/s.
What is the motion of the motorbike?The motion of the motorbike can be described as linear type of motion since the distance travelled by the motorbike increases with increase in the time of motion.
There is directly linear relationship between the distance travelled by the motorbike and the time of motion of the motorbike.
The distance travelled by the motorbike is calculated as follows;
from the given graph, at time 30 seconds, the corresponding the distance of the motorbike on the vertical axis is 600 m.
distance = 600 m
The speed of the motorbike is calculated as follows;
v = d/t
v = 600 m / 30 s
v = 20 m/s
Thus, the motion of the motorbike is a linear type of motion, the distance travelled by the motorbike increases with increase in the time of motion and the speed of the motorbike depends on the distance and time of motion.
Learn more about speed here: https://brainly.com/question/6504879
#SPJ1
A railroad locomotive is at rest with its whistle shrieking and then it starts moving toward you. Describe what happens to the frequency and wavelength of the sound that hits your ear when:A) It is approaching you.B) It pulls away from you.What happens to the amplitude in both of these scenarios?
a) Frequency increases , the time between waves decreases , wavelenghts decrease
b) Frequency decreases , wavelenght increases.
The doppler effect is a change in the frequency of sound waves that occurs when the source of the sound waves is moving relative to a stationary listener. AS the source approaches the listener , the sound waves get closer together, increasing their frequency and decreasing their wavelenghts.
Amplitude remains the same.
Can anyone tell me the final displacement of the puck
The final displacement of the puck is 4.14i + 14.14j
What is displacement?Displacement is the change in position of an object.
How to find the final displacement of the puck?Since for the first displacement of the puck from the goal is 20 m at 45°, we have that its displacement vector is d = (20cos 45°)i + (20sin45°)j.
= (20 × 0.7071)i + (20 × 0.7071)j.
= 14.14i + 14.14j
Also, for the second displacement is 10 m to the left. Its displacement vector is d' = -10i
So, we see that the total displacement is D = d + d'
So, adding the displacements, we have D = d + d'
= 14.14i + 14.14j + (-10i)
= 14.14i - 10i + 14.14j
= 4.14i + 14.14j
So, we see that the final displacement of the puck is 4.14i + 14.14j
Learn more about the displacement here:
https://brainly.com/question/28569699
#SPJ1
Many scientists believe the solar system formed _______________ago
Answer:
4.6/4.5 billion years ago
Explanation:
Which characteristic will be affected by increasing the speed of an object from 30 mph to 40 mph?
gravitational attraction
weight
kinetic energy
mass
Answer:
Kinetic energy
Explanation:
Kinetic energy of an object is directly proportional to the square of its speed (or velocity). An increase in speed will increase the kinetic energy.
In (Figure 1) a 6.00-m-long, uniform beam is hanging from a point 1.00 m to the right of its center. The beam weighs 155 N and makes an angle of 30.0∘ with the vertical. At the right-hand end of the beam a 100.0 N weight is hung; an unknown weight w hangs at the left end.If the system is in equilibrium, what is w ? You can ignore the thickness of the beam.
Given::
Length = 6.00 m
Weight of beam = 155 N
Angle = 30.0 degrees
Weight added at the right-end = 100 N
If the system is in equilibrium, let's find the weight, w, at the left-end.
Since the system is in equilibrium, the net torque of the system will be zero.
Now, we have the equation:
[tex](100)(2.00sin30)-w(4.00sin30)-(155)(1.0sin30)=0[/tex]Where w is the weight at the left end.
Let's solve for w.
We have:
[tex]\begin{gathered} (100)(1)-w(2)-(155)(0.5)=0 \\ \\ 100-2w-77.5=0 \\ \\ 100-77.5-2w=0 \end{gathered}[/tex]Solving further:
[tex]\begin{gathered} 22.5-2w=0 \\ \\ 2w=22.5 \end{gathered}[/tex]Divide both sides by 2:
[tex]\begin{gathered} \frac{2w}{2}=\frac{22.5}{2} \\ \\ w=11.25\text{ N} \end{gathered}[/tex]Therefore, the weight hung at the left end is 11.25 N
ANSWER:
11.25 N
A helium balloon has a volume of 8.89 liters, or 0.00889 cubic meters. Air has a density of 1.29 kilograms per cubic meter, and helium has a density of 0.177 kilograms per cubic meter.a. What is the weight of the helium inside the balloon?b. What is the buoyant force exerted on the balloon?c. What is the net force on the balloon? Neglect the weight of the rubbery material that comprises the actual balloon. . How many identical balloons would be needed to lift a child of mass 24.9 kilograms?
Given:
The volume of a helium balloon: 8.89 liters or 0.00889 cubic meters
The density of helium: 0.177 kilograms per cubic meters
The density of the air: 1.29 kilograms per cubic meters
To find:
a) weight of the helium inside the balloon.
b) the buoyant force exerted on the balloon.
c) the net force on the balloon.
d) number of identical balloons needed to lift a child of mass 24.9 kilograms.
Explanation:
a)
The expression for the density of the balloon is:
[tex]Density\text{ of helium=}\frac{Mass\text{ of helium}}{Volume\text{ of helium}}[/tex]Rearrange the above expression to find the mass of the helium.
[tex]Mass\text{ of helium=Density of helium}\times Volume\text{ of helium}[/tex]Substitute the values from the given data, we get:
[tex]\begin{gathered} Mass\text{ of helium=0.177}\frac{kg}{m^3}\times0.00889\text{ m}^3 \\ Mass\text{ of helium=0.001573 kg} \end{gathered}[/tex]Thus, the mass of the helium is 0.001573 kg.
The weight of an object is the product of its mass and gravitational acceleration. Thus, the weight of helium is
[tex]\begin{gathered} Weight\text{ of helium=mass of helium}\times g \\ \end{gathered}[/tex]here, g is the acceleration due to gravity.
Substitute the values, and we get:
[tex]\begin{gathered} Weight\text{ of helium=0.001573 kg }\times9.8\text{ }\frac{m}{s^2} \\ Weight\text{ of helium=0.01542 N} \end{gathered}[/tex]The weight of helium is 0.001542 Newtons.
b)
The expression for buoyant force is:
[tex]F=\rho gV[/tex]here, ρ is the density, g is the acceleration due to gravity and V is the volume.
To find the buoyant force exerted by helium on the balloon, substitute the values for helium in the above equation.
[tex]\begin{gathered} F=0.177\text{ }\frac{kg}{m^3}\times9.8\text{ }\frac{m}{s^2}\times0.00889\text{ m}^3 \\ F=0.01542\text{ }\frac{kg\cdot m}{s^2} \\ F=0.01542\text{ N} \end{gathered}[/tex]The buoyant force exerted on the baloon is 0.01542 Newtons.
c)
The buoyant force exerted by the balloon is 0.01542 N and it acts in an upward direction. Whereas, the other force acting on the balloon is the force due to gravity, the weight of the balloon. The weight of the balloon is 0.01542 N and is always acts in the downwards direction.
Since the magnitude of buoyant force exerted on a balloon is equal to the weight of the balloon. Both these forces are acting in opposite directions. Thus the net effect will be zero.
[tex]\begin{gathered} F_{net}=F-W \\ F_{net}=0.01542\text{ N -0.01542 N} \\ F_{net}=0\text{ N} \end{gathered}[/tex]Thus, the net force acting on the balloon is 0 Newtons.
d)
For a helium balloon, 1 liter of helium can lift 1 gram of mass.
The mass of the child is 24.9 kg = 24900 grams.
Thus, to lift a child of mass 24900 grams, 24900 liters of helium is required.
Now, one balloon contains 8.89 liters of helium, thus for 24900 liters of helium volume, the number of ballons required will be,
[tex]\frac{1\text{ balloon}}{n\text{ balloons}}=\frac{8.89\text{ liters}}{24900\text{ liters}}[/tex]Rearranging above equation to find n, we get
[tex]\begin{gathered} n\text{ balloons = }\frac{24900}{8.89} \\ n\text{ balloons = 2800.89} \end{gathered}[/tex]Thus, approximately 2801 helium balloons are required to lift a child of mass 24.9 kg.
Final answer:
a) The weight of helium is 0.001542 Newtons.
b) The weight of helium is 0.001542 Newtons.
c) The net force acting on the balloon is 0 Newtons.
d) Approximately 2801 helium balloons are required to lift a child of mass 24.9 kg.
A= 1/2 W (R+S) for W
The change of the subject in the formula is given by; W = 2A/(R + S)
How do we make a subject in formula?When we have a formula, each of the components of the formula are the parameters of the formula. In this case, we have a formula that says A= 1/2 W (R+S). The parameters that are in this formula are A, W, R and S.
According to the question, we have been asked to make W the subject of the formula.
The first step is to multiply both sides by 2
2A = W(R + S)
And secondly, we divide both sides by the sum of R and S and we have;
W = 2A/(R + S)
Learn more about subject in formula:https://brainly.com/question/19107883
#SPJ1
What is the range of motion(far,medium,or short) in these state of matters:
Neon:
Argon:
Oxygen:
Water:
thank you!
A water bed that is 1.5 m wide and 2.5 m long weighs 1055 N. Assuming the entire lower surface of the bed is in contact with the floor, what is the pressure the bed exerts on the floor?
a.
250 Pa
c.
270 Pa
b.
260 Pa
d.
280 Pa
Explain how this sand dune was created using the words weathering, erosion, and deposition.
PLSSS HELPP
By abrasion, the sediment in the wind promotes erosion. The wind scatters sand, sand dunes created. When clay and silt are deposited by the wind. The presence of vegetation ground helps stop wind erosion.
What is an erosion ?Earthen materials were worn away during erosion, a geological process in which they are moved by water or wind. Weathering, a related process that does not involve movement, dissolves and breaks down rock.
What is caused by erosion?The process through which the Earth's surface ages is known as erosion. Natural forces like wind or glacier ice can create erosion. But when it comes to altering the Earth, nothing compares to a slow, constant movement of water, as anyone who has ever seen a picture of a Grand Canyon will attest.
To know more about Erosion visit:
https://brainly.com/question/3852201
#SPJ13
1) speed of bob?2)Show calculation for the speed of the bob:(write formula first, then insert value with unit, then find the result with unit)
Speed of bob:
[tex]\begin{gathered} \omega=2\pi f \\ _{\text{ }}where\colon \\ f=\frac{1}{T} \\ \omega=\frac{2\pi}{T} \end{gathered}[/tex]so:
[tex]\begin{gathered} \omega=\frac{2\pi}{1.293} \\ \omega=4.83\frac{rad}{s} \end{gathered}[/tex][tex]\begin{gathered} v=\omega\cdot r \\ so\colon \\ v=4.83\cdot0.22 \\ v=1.06\frac{m}{s} \end{gathered}[/tex]
Which is true of the force pair of Newton's third law?a.)The two forces are in the same direction.b.)The two forces never produce an acceleration. c.)The two forces act on different objects.
Given:
Force pair of Newton's third law.
Required:
To find the true statement for the force pair of Newton's third law.
Explanation:
According to Newton's third law
This can be understood by taking an example.
Suppose a person hits the wall with his hand, the person hitting the wall is the action.
This action results in pain in the person's hand which is the reaction.
Here, the hand exerted force on the wall and the wall exerted an equal force in opposite direction.
The conclusion can be drawn as
Action and reaction act on two different objects.
The forces act in opposite direction.
Final Answer: The two forces act on different objects.
Graphing is a way to represent data visually to represent the motion of a rolling ball students craft data on A-line graph which of the following would accurately label the X ax
Such an object lacks a velocity since it lacks a slope. Such an object must have a variable velocity. It's quickening.
Which kind of graph is utilized for motion?Starting off, let's graph a few instances of motion with constant speed. The graph on the right shows three alternative curves, each with a zero initial point. The first thing to note is how straight each graph is. (On a graph, a curve can be any type of line that is drawn.
It is not possible to determine the velocity from a position-time graph's slope when the graph is curved. Only straight lines have slope as a characteristic. Such an object lacks a velocity since it lacks a slope. Words like "the" and "a" are highlighted in this text to emphasize that there isn't a single velocity for these conditions. Such an object must have a variable velocity. It's quickening.
To know more about position-time graph's visit:-
https://brainly.com/question/13693087
#SPJ13
When you drop a 0.36 kg apple, Earth ex- erts a force on it that accelerates it at 9.8 m/s² toward the earth's surface. According to New- ton's third law, the apple must exert an equal but opposite force on Earth. If the mass of the earth 5.98 x 1024 kg, what is the magnitude of the earth's acceleration toward the apple? Answer in units of m/s². Answer in units of m/s^2
The magnitude of the earth's acceleration toward the apple is 5.7x10^-25 m/s^2
Given:
Mass if the apple (m)= 0.36
Mass of the earth (M)=5.98x10^24
Gravitational acceleration (g)= 9.8
we know that the formula is:
Ma=mg
So, according tot the formula
a=(m/M)g
=(0.36/5.98x10^24)9.8
=5.7x10^-25 m/s^2
Learn more about mangnitude of earth's acceleration.
https://brainly.com/question/4035431
#SPJ9
I don't know what I'm doing wrong I just can't seem to get the answers right. Help please.
The current and potential difference in the lumped element model of electrical circuits are dealt with by Kirchhoff's circuit laws, which are two equalities. German scientist Gustav Kirchhoff published the first account of them in 1845. This was done before James Clerk Maxwell and generalized Georg Ohm's work.
Because the sum of the currents entering and leaving the junction is equal, Kirchhoff's first law is based on the conservation of charge. The algebraic sum of potential drops in a closed circuit must equal zero, according to Kirchhoff's second law. Therefore, it is based on energy conservation.
A stream of charged particles—such as electrons or ions—moving through a conductor for electricity or into empty space is known as an electric current. It is determined by measuring the net rate of electric charge flow through a surface or into a control volume.
The amount of resistance in an electrical circuit represents the resistance to current flow. The Greek letter omega (Ω), which stands for resistance, represents ohms.
To know more about circuits, click on the link below:
https://brainly.com/question/2969220
#SPJ9
During which season does the north pole experience constant sunlight?
A. spring
B. winter
C. summer
D. autumn
During the summer season, the north pole gets constant sunlight.
How does the north pole experience constant sunlight?In the summer season, the north pole experience constant sunlight. Because in the summer the shadows are short and the sun remains higher in the sky. In the summertime, the sun remains above the horizon at the north pole which circles the pole every day.
In the summer the sun's rays reach the north pole while in winter season the north pole is tilted away from the incoming sunshine. Mostly the regions of the north pole remain cold because the sunlight does not directly fall on the north pole. At the north pole, there are only two types of seasons, one is summer and the other is winter season. The annual average temperature of the winter season at the north pole is -40 degrees Celsius while in summer season the average temperature is 32 F.
So we can conclude that during the months of the summer season the north pole gets maximum sunlight.
Learn more about the North Pole here: https://brainly.com/question/18944268
#SPJ1
A cell of a constant e. m.f is connected in series with a parallel arrangement of 8ohms coil and a uniform wire of length (Lcm). The total external resistance in the circuit is found to be 6ohms. calculate the resistance of the wire and its length. Resistivity of the wire material = 6.0×10^-5 ohm/meter, cross-sectional area of the wire = 6.0×10^-3cm².
The resistance of the wire will be 24ohm and the length of the wire will be 24×10⁴cm.
As given in the question,
Rₜₒₜₐₗ = 6ohm
Resistivity = 6×10⁻⁵ohm/m = 6×10⁻⁵/100ohm/cm
Area(A)= 6×10⁻³cm²
Let R = resistance of the wire, therefore;
Rₜₒₜₐₗ = R×8 / R+8
6 = R×8 / R+8
6R + 48 = 8R
48 = 2R
R = 24ohm
R = 24ohm
we know that resistance (R)=rho×l/A
Therefore,
rho×l/A = 24
6×10⁻⁵/100 × l/6×10⁻³ = 24
10⁻⁴ × l = 24
l = 24×10⁴cm
So, the resistance of the wire will be R=24ohm and the length of the wire will be 24×10⁴cm.
Learn to know more about resistance on
https://brainly.com/question/28135236
#SPJ9
How do we meet the needs of humanity in a sustainable way
We can fulfill the need of humanity by providing them jobs, resources, clean water, good energy, and electricity and by providing many facilities.
Why do we sustainably help humanity?We can sustain our need for humanity in many ways which are given below.
First of all, we need to decrease the rate of poverty and hunger to make humanity prosperous. We should provide jobs for those people who are free. We should provide good hospitals and a well-planned health system. We should provide a good and quality education system for the improvement of humanity. Provide clean water and make ways for sanitation. We should provide affordable and clean energy to humanity which should be cheap but not expensive. We should work decently together and provide resources for economic growth. We should sustainably develop our countries because developing involves satisfying the needs of the present population without endangering the capability of the future population to satisfy its own needs.
So we can conclude that providing jobs, resources, clean water, good energy, and electricity, and many facilities to humans is the help of humanity.
Learn more about Humanity here: https://brainly.com/question/27438014
#SPJ1
Jimmy launches his rocket straight up with an initial velocity of 25 m/s.a. What is the velocity as the rocket reaches maximum height?b. How long will it take the rocket to reach its maximum height?
Given that the initial velocity is u = 25 m/s.
We have to find the final velocity and time at its maximum height.
First, we need to find the maximum height.
[tex]h\text{ =}\frac{u}{2g}[/tex]Here, g = 9.81 m/s^2 is the acceleration due to gravity.
Substituting the values, the height will be
[tex]\begin{gathered} h=\text{ }\frac{25}{2\times9.81} \\ =1.274\text{ m} \end{gathered}[/tex](a) Let the final velocity be v.
The formula to calculate final velocity is
[tex]\begin{gathered} v^2=u^2-2gh^{} \\ v=\sqrt[]{u^2-2gh^{}} \end{gathered}[/tex]Substituting the values, the final velocity will be
[tex]\begin{gathered} v=\sqrt[]{\lbrack(25)^2-(2\times9.81\times1.274)\rbrack} \\ =\sqrt[]{600.01} \\ =24.49\text{ m/s} \end{gathered}[/tex](b) The time taken can be calculated by the formula,
[tex]\begin{gathered} t=\frac{v-u}{-g} \\ =\frac{24.49-25}{-9.81} \\ =0.051\text{ s} \end{gathered}[/tex]Thus, the final velocity is 24.49 m/s and time is 0.051 s
The potential energy for a mass on a spring is proportional to the square of which of these quantities?
A. mass
B. frequency
C. displacement
E. period displacement velocity
Answer:
C. Displacement
Explanation:
How do I find if the dog is accelerating or not?
We will have the following:
* The dog walks at a constant speed of 1 m/s in a straight line east. [Not accelerating].
* The dog speeds up from 1 m/s to 7 m/s as he runs away from a cat that scared him. [Accelerating].
* The dog walks at a constant speed of 0.5 m/s in a circle around a bowl of food. [Not accelerating].
* The dog stand in one spot on his bed. [Not accelerating].
* The dog slows down to a stop as he approaches the fence at the edge of the yard. [Accelerating].
At room temperature, most metals are
A. Solids
B. Liquids
C. Gases
D. Plasma
Answer:
A. Solids
Explanation:
only Mercury is liquid soo .... solid
A particular cookie provides 54.0 kcal of energy. An athlete does an exercise that involves repeatedly lifting (without acceleration) a 103-kilogram weight 2.45-decimeters above the ground with an energy efficiency of 25%. How many repetitions of this exercise can the athlete do with the energy supplied from one of these cookies?
The maximum quantity of repetitions that the athlete could complete with their current level of energy was 229 for such a workout.
Energy efficiency is the ratio of input power to energy output. As just a result, a cookie contains 54.0 kcal in calories. An athlete utilizes the 54.0 kcal in just this cookie for input energy.
The following formula could be employed to measure efficiency:
Energy intake minus power generated is efficiency.
Efficiency = output energy / input energy
After rearrangement above equation.
output energy = efficiency × input energy
Put the given data in above equation.
Output energy = 0.25 × 54 kcal = 13.5 kcal.
Again for power capacity, the lifting exercise was already carried out n times. The source of total output energy is mgh within the form of electromagnetic potential.
So, Energy per repetition = mgh
Where, m will represent mass g will represent gravity h is height.
By entering the data provided above.
Energy per repetition = 103 kg × 9.8 m/[tex]s^{2}[/tex] × (2.45 × 0.1m)
Energy per repetition= 247.303 J
Energy per repetition = 0.059 kcal.
So, quantity of repetitions = overall output energy / energy per repetition
quantity of repetitions = 13.5 kcal / 0.059 kcal
quantity of repetitions will be equal to 229 repetitions.
Therefore, the quantity of repetition would be be 229.
To learn more about energy efficiency click here https://brainly.com/question/866594
#SPJ1
7. Determine the resistance of a lamp that draws 3 amperes when connected to a120-volt supply
A lamp draws 3 amperes of current and is connected to a 120 volt supply.
We are asked to find the resistance of the lamp.
Recall the Ohm's law is given by
[tex]V=IR[/tex]Where V is the voltage, I is current, and R is the resistance.
Re-arrange the equation for resistance
[tex]R=\frac{V}{I}[/tex]Substitute the given values
[tex]\begin{gathered} R=\frac{120}{3} \\ R=40\; \Omega \end{gathered}[/tex]Therefore, the resistance of the lamp is 40 ohms.
What is the equation for the X axis of this fbd? Remember the sign of convention discussed in the module
F - f = ma
Explanation:The sum of forces on the x-axis = ma (since it is not stated that the forces are in equilibrium)
[tex]\sum fx=ma[/tex]By resolving the Free Body
[tex]F+(-f)=ma[/tex]Simplifying the equation above, we have:
F - f = ma
A ball is thrown downwards from a height of 25m with an initial velocity of 10 m/s.
Find the velocity of the ball just before it hits the ground.
•V₁=10mls
h=25m
The velocity of the ball just before it hits the ground is 24.29m/s.
What is acceleration due to gravity?
The acceleration an object experiences as a result of gravitational force is known as acceleration due to gravity. M/s2 is its SI unit. Its vector nature—which includes both magnitude and direction—makes it a quantity. The unit g stands for gravitational acceleration. At sea level, the standard value of g on earth's surface is 9.8 m/s2.
Given:
Initial velocity u = 10m/s
height h = 25m
we know that the acceleration due to gravity g is : 9.8m/s
Therefore using the formula,
v² - u² = 2gs where s is the height in this case and v is the final velocity.
v² - 10² = 2 x 9.8 x 25
=> v² = 490 + 100
=> v = √590
=> v = 24.29m/s
To learn more about velocity click on the link below:
https://brainly.com/question/24681896
#SPJ9
The double-sided mirror would produce virtual image to which objects? A)1,2 and 4 B)1,2 and 3 C)3 and 5 D)4 and 5
Objects 3 and 5.
Virtual images are always formed by convex mirrors and are formed by concave mirrors when the object is placed in front of f.