Answer:
speed of object after 2 seconds will be 6 ms⁻¹
Explanation:
Initial velocity = 0
Final Velocity = 21 m/s
Time = 7 sec
We need to find speed of object after 2.0 seconds.
First we will find acceleration using formula: [tex]Accelaration=\frac{change \ in \ velocity}{change \ in \ time}[/tex]
Putting values:
[tex]Accelaration=\frac{Change \ in \ velocity}{Change \ in \ time}\\Accelaration=\frac{21-0}{7}\\Accelaration=\frac{21}{7}\\Accelaration= 3 \ ms^{-2}[/tex]
Now finding speed of object after 2 seconds
The formula used will be: [tex]Speed(v) = a\times t+v_0[/tex]
Putting values of a= 3m/s², t=2 sec and v₀=0 (at rest)
[tex]Speed(v) = a\times t+v_0\\Speed(v) = 3\times 2+0\\Speed(v) =6\ ms^{-1}[/tex]
So, speed of object after 2 seconds will be 6 ms⁻¹
During the "Power Lab", Andrew runs up the stairs, elevating his 79.5 kg body a vertical distance of 2.29 meters in a time of 1.32 seconds. Calculate the power generated by Andrew. (g = 9.8 m/s2)
Answer:
1351.62 Watts.
Explanation:
The following data were obtained from the question:
Mass (m) = 79.5 kg
Height (h) = 2.29 m
Time (t) = 1.32 s
Acceleration due to gravity (g) = 9.8 m/s²
Power =?
Next, we shall determine the potential energy of the boy. This can be obtained as follow:
Potential energy (PE) = mass × acceleration × height
PE = m × g × h
Mass (m) = 79.5 kg
Height (h) = 2.29 m
Acceleration due to gravity (g) = 9.8 m/s²
Potential energy (PE) =?
PE = m × g × h
PE = 79.5 × 9.8 × 2.29
PE = 1784.139 J
Finally, we shall determine the power generated by Andrew as illustrated below:
Energy (E) = 1784.139 J
Time (t) = 1.32 s
Power (P) =?
P = E/t
P = 1784.139 /1.32
P = 1351.62 watts
Therefore, the power generated by Andrew was 1351.62 watts
A ball of mass m is suspended from two strings of unequal length as shown. The magnitude of the tensions T1 and T2 in strings must satisfy which of the following relations?
Let θ₁ and θ₂ denote the angles made by the tension forces T₁ and T₂ with the positive horizontal axis (directly to the right), respectively. (BTW, I write T₁ in boldface for the vector and T₁ for its magnitude.)
The ball is kept in equilibrium, so by Newton's second law both the net horizontal and net vertical forces are zero. This means
[1] T₁ cos(θ₁) + T₂ cos(θ₂) = 0
[2] T₁ sin(θ₁) + T₂ sin(θ₂) - m g = 0
Both cos(x) and sin(x) fall within -1 and 1 for any angle x, so right away we know that
T₁ sin(θ₁) + T₂ sin(θ₂) ≠ T₁ + T₂
so option (B) is not correct.
If T₁ = T₂, then in equation [1] we get
T₁ cos(θ₁) + T₁ cos(θ₂) = 0
T₁ (cos(θ₁) + cos(θ₂)) = 0
cos(θ₁) + cos(θ₂) = 0
which means θ₁ = 180° - θ₂, since cos(180° - x) = - cos(x) for any x. But this would require both strings to have the same length. So option (C) is also not correct.
The horizontal components of T₁ and T₂ are the only forces acting in the horizontal direction, so their horizontal components are equal. However, the vertical component of T₂ is closer to being parallel to the weight of the ball, which means T₂'s vertical component is almost enough on its own to counteract the ball's weight. This in turn means that (D)T₂ > T₁.
In other words, sin(θ₂) is closer to 1 than sin(θ₁), and T₂ is closer to m g than T₁.
Radha was making coffee for her sister. She stopped stirring coffee but swirling motion continued for some time .She was wondering how this can happen .Can you help her in explaining in terms of inertia
Answer:
Explanation:
Inertia is one of the major properties of all objects which makes an object at rest to be reluctant to move and an object in motion to be reluctant to stop.
Therefore during the stirring of the coffee, the molecules of the mixture were in a continuous circular motion. But after the stirring has ceased, the molecules were reluctant to stop. Thus the motion continues for sometime until some available damping forces acts.
Thus the observation by Radha with respect to the motion of the coffee.
Which statement is a scientifically accurate description of velocity?
The motorcyclist traveled along a highway at 55 mph and reached the campsite in less than the two-hour estimated time.
Walking south along the two-mile canyon trail generally takes less time than traveling the same trail north because walking south is all downhill.
The hiker began hiking the park's five-mile north hiking trail at 8:00 a.m. with plenty of daylight left to complete the hike before dark.
The boat traveled from the dock north to the 200-meter marker in the bay in less than 5 minutes, giving the passengers several more hours to fish.
Answer The last one is you answer
Explanation:
The boat traveled from the dock north to the 200-meter marker in the bay in less than 5 minutes, giving the passengers several more hours to fish. This statement is scientifically accurate description of velocity.
What is velocity?The rate at which a body's displacement changes in relation to time is known as its velocity. Velocity is a vector quantity with both magnitude and direction. SI unit of velocity is meter/second.
The boat traveled from the dock north to the 200-meter marker in the bay in less than 5 minutes. In this statement both magnitude and direction is given. From this statement, the velocity of the boat is:
= 200/5 meter/minute in north direction.
= 40 meter/minute in north direction.
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what is force x time is called
Answer:
In words, it could be said that the force times the time equals the mass times the change in velocity. In physics, the quantity Force • time is known as impulse. And since the quantity m•v is the momentum, the quantity m•Δv must be the change in momentum. The equation really says that the Impulse = Change in momentum.
If a substance containing charged ions and electrons can be compressed so that the particles have less space between them, the substance is a
gas.
plasma.
solid.
liquid.
Answer: plasma
Explanation: plasma has charged particles called ions, and free electrons
Pls a good 6th grade science project pls I will give you a lot of points
Pls
And it has to be cheap and from science
Answer:
you do a chemical reaction thing
Explanation:
get baking soda and mix it with b
vinegar and then try other liquids on baking soda and see the reaction, make sure to document and take pictures
9. To completely describe the motion of an object, you need
a. Position
b. Speed
C. Direction of motion
d. All of the above
What is the purpose of setting a deadline for a goal?
Answer:
To help push yourself to reach the goal, It can also help you pace yourself time wise
Explanation:
How does the total kinetic energy equation of a cannonball system change as mass of the cannon increases and the energy of the blast remains the same?
A. The total kinetic energy cannot be determined.
B. The total kinetic energy decreases.
C. The total kinetic energy increases.
D. The total kinetic energy remains the same.
When the mass of the cannon increases and the energy of the blast remains the same, the total kinetic energy remains the same.
Kinetic energy refers to the form of energy that an object possesses due to its motion. It is known as the work that's required to move a body.
It should be noted that when there is an increase in the mass of the cannon while the energy of the blast remains the same, then in such a situation, the total kinetic energy will remain the same.
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Why is it important to practice preventive measure when engaging in both indoor and outdoor physical activities?
Answer:
Abstract
There are strong evidences linking physical outdoor activity and health benefits; however, little is known about the impact on environmental behaviors. Thus, this study aims to close this gap by investigating the influence of physical outdoor activity on environmental behaviors. A total of 416 surveys were distributed to students in eight public primary schools located near the Hsinchu Science and Industrial Park in Taiwan. Findings from the analysis revealed that subjective norms had a more influential effect on environmental behaviors for participants who engaged in physical activity at outdoor parks. In contrast, descriptive norms had a direct predictive impact on environmental behaviors for participants whose main physical activity venue was at the indoor after-school centers. Research results also highlighted attitude as the strongest predictive variable influence on environmental behaviors for children who engaged in physical indoor and outdoor activities
Explanation:
hula ko lng yan
Explain how magnetic stripes on the ocean floor are evidence for sea-floor spreading.
Answer:
Explanation:
•Scientists have found that the rocks that make up the seabed are hidden in their "threads". This strip contains a record of the rotation of the Earth's magnetic field. The rocks on the seabed contain iron. ... When the rock cools down, the iron fragments inside align with the direction of the Earth's magnetic poles.
17.food that is both nutrient- and calorie-dense can be a good choice in what circumstance?
A. When it is high-glycemic
B.When it contains trans fats
C.When it contains more than 400 calories per serving
D.When it is portion-controlled
Answer:
Explanation: you can choose B or C but i would choose C
.An iron nail sinks in water but a ship made of the same materials floats on water. why?
Answer:
Because their is an air pocket at the bottom of a boat air is lighter than water so it floats
Explanation:
....
Answer:
lau aba clear hunxau timi
Ms. Mann's experiment illustrates several important facts in science
that include ALL BUT ONE of those listed here.
A)
Like charges repel.
B) Opposite charges repel.
C)
Friction can cause a transfer of charge.
D)
Attractive forces can work at a distance.
Answer:
(B)
Explanation:
I did it in USATestprep.
Ms. Mann's experiment illustrates several important facts in science that include all except for Opposite charges repel, as opposite charges attract. Thus, the correct option for this question is B.
What is a Scientific experiment?A scientific experiment may be characterized as a type of scientific test or investigation in which you have to perform a sequence of actions and carefully observe their consequences in order to derive some logical and unknowing facts.
According to the context of this question, like charges always repel one another, while opposite charges may definitely attract to each other. Friction can cause a transfer of charge from one object to another. Attractive forces can work at a distance.
Therefore, Ms. Mann's experiment illustrates several important facts in science that include all except for Opposite charges repel, as opposite charges attract. Thus, the correct option for this question is B.
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37 Questions - All Questions Are Required
Score 1
2 A car's velocity decreases from 22.0 m/s to 10.0 m/s over a period of 3.0 s. What is the car's average acceleration?
The required car average acceleration over a period of 3.0 s is -4.0 m/s².
What is acceleration?The rate of change of velocity with respect to time is called acceleration.
Here,
The average acceleration of a body is given by the formula,
average acceleration = (final velocity - initial velocity) / time taken
In this case, the initial velocity of the car is 22.0 m/s, the final velocity is 10.0 m/s, and the time taken is 3.0 s. Therefore, the average acceleration of the car can be calculated as:
average acceleration = (10.0 m/s - 22.0 m/s) / 3.0 s
average acceleration = -12.0 m/s² / 3.0 s
average acceleration = -4.0 m/s²
Note that the negative sign indicates that the car is decelerating, or slowing down.
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The sound level in a certain seat at the movie theater is higher than the level in the surrounding seats. Which wave interaction can help to explain why?
Absorption
Reflection
Destructive interference
Constructive inference
A p e x
Answer: constructive interference
Explanation: plz mark Brainly
Answer:
constructive interference
Explanation:
a p e x :))
20 J of energy was used to
stretch a spring with a
spring constant of 445 N/m,
what is the final extension
of the spring?
Answer:
0.3m
Explanation:
Given parameters;
Elastic energy = 20J
Spring constant = 445N/m
Unknown
Final extension of the spring = ?
Solution:
The elastic potential energy of a stretched spring can be determined using the expression below;
EP = [tex]\frac{1}{2}[/tex] k e²
k is the spring constant
e is the extension
Insert the parameters and solve;
20 = [tex]\frac{1}{2}[/tex] x 445 x e²
multiply those sides by 2;
2(20) = 445e²
40 = 445e²
e² = [tex]\frac{40}{445}[/tex] = 0.09
e = √0.09 = 0.3m
A copper wire is connected across a constant voltage source. Which change will cause an increase in the current flowing through the wire? A. an increase in the length of the wire B. an increase in the resistance of the wire C. an increase in the diameter of the wire D. an increase in the insulation around the wire
Answer:
B
Explanation:
"The more conductive something is, the less resistance it will have."
A copper wire is connected across a constant voltage source. An increase in the length of the wire will cause an increase in the current flowing through the wire.
What is resistance of wire?Resistance is proportional to resistivity and length, and inversely proportional to cross sectional area.
[tex]R =\dfrac{\rho l}{A}[/tex]
Where,
ρ is resistivity of wire which is same for a material.
[tex]l[/tex] is length of wire.
[tex]A[/tex] is cross sectional area .
For constant voltage and increase in current flowing through the wire, one have to increase the resistance of the wire. That means we have to increase the length of wire.
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If a Ferrari, with an initial velocity of 14m/s, accelerates at a rate of 60 m/s^2 for 4 seconds, what will its final velocity be
Answer:
254 m/s
Explanation:
(Vf-Vi) = at
(Vf-14)= 60 (4)
Vf = 254 m/s
What are one or two things that you know about collisions?
Answer: In science collisions can be elastic, meaning they conserve both momentum and kinetic energy, or inelastic, meaning they conserve momentum but not kinetic energy.
Explanation: I hope that helped yall!
i cant belive im doing this- i will mark brainliest if this gets answered- mostly correct.
What will this be ? Help me out
Answer:
7: C 8:All of These
Explanation:
Im almost 100% sure on both of these. Feedback is like critism and you'll get nowhere focusing on all good and no bad. You can't go to the doctor on your own if you're a child for technically it's both yours and your parents. Your teacher is responsible for notifying your parents and you are responsible for telling your teacher.
cells are considered the smallest part of an organsim that can?
A ball is kicked off a 75 m tall cliff with a horizontal velocity of 5 m/s. How long till it reaches the ground? How far will the ball land from the base of the cliff?
Let, time taken is t.
So,
[tex]s=ut + \dfrac{gt^2}{2}\\\\75 = 0 + \dfrac{10\times t^2}{2}\\\\150=10\times t^2\\\\t = \sqrt{15}\\\\t = 3.873\ s[/tex] ( Here, us is vertical component of initial velocity )
Now, distance covered from the base of the cliff is :
[tex]D=5\times 3.873\ m\\\\D = 19.365\ m[/tex]
Therefore, time taken and distance covered is 3.873 s and 19.365 m.
Hence, this is the required solution.
Ma of a machine is always less than Vr
Answer:
MA of a machine is always less than VR.
Explanation:
It is because mechanical advantage decreases due to the friction and weight of moving parts of the machine whereas the velocity ratio remains constant.
Which has only a thin atmosphere?
Answer:
Mercury
Mercury. Mercury is the smallest terrestrial planet in the solar system, about a third the size of Earth. It has a thin atmosphere, which causes it to swing between burning and freezing temperatures.
Explanation:
hope it helps, mark brainliest please
A 3.00 kg crate is pulled along a frictionless surface with a force of 55.0 N at 25.00 to the
horizontal so that it accelerates directly to the right. What is the crate's acceleration?
ALGEBRA Find x and the measures of the unknown sides of each triangle.
12.
M
13.
R
17
Sx
6x - 5
2x + 7
2
N
O
5
3x - 4
3x + 10
+
9514 1404 393
Answer:
12. x = 11; sides are 29
13. x = 5; sides are 25
Explanation:
12. The marked sides are equal length, so ...
3x -4 = 2x +7
x = 11 . . . . . . . . add 4-2x
2x+7 = 2(11)+7 = 29 . . . side lengths
__
13. The marked sides are equal length, so ...
6x -5 = 5x
x = 5 . . . . . . . add 5-5x
5x = 5(5) = 25 . . . side lengths
Summarize Dr. Hillmans's research with students sitting and walking. ASAP pls
Answer:
shut up
Explanation:
and watch the video lazy bum