Answer:
Explanation:
(a) Electromagnetic waves travels at the speed of light = 3.0 x [tex]10^{8}[/tex] m/s.
v = fλ
where v is the velocity of the wave, f is the frequency, and λ wavelength.
So that;
λ = [tex]\frac{v}{f}[/tex]
= [tex]\frac{3.0*10^{8} }{87.9*10^{6} }[/tex]
= 3.413 m
ii. Enegy of the wave can be determined by;
E = hf
where h is the Planck's constant and f the frequency of the wave.
E = 6.626 x [tex]10^{-34}[/tex] x 87.9 x [tex]10^{6}[/tex]
= 5.82 x [tex]10^{-26}[/tex] J
(b) Refractive index of water = [tex]\frac{velocity of light in air}{velocity of light in water}[/tex]
velocity of light in water = 1.33 x 3.0 x [tex]10^{8}[/tex]
= 3.99 x [tex]10^{8}[/tex] m/s
if you weigh 88 N on the moon when the gravity 1.6m/s2 what is your mass
An earthquake has just occurred in the North Pole. Could detectors in the South Pole detect the S wave?
Answer:
YES THEY CAN
Explanation:
SOUTH POLE IS CLOSER TO NORTH POLE,kinda
What characteristics consider as consider as foundation of an effective officiating official?
A competence
B compassion
C confidence
D courage
Answer:
c
Explanation:
what is the kinetic energy of a 7.26 kg bowling ball that is rolling at a speed of 2m/s
Answer:
14.52 JExplanation:
The kinetic energy of an object can be found by using the formula
[tex]k = \frac{1}{2} m {v}^{2} \\ [/tex]
m is the mass
v is the velocity
From the question we have
[tex]k = \frac{1}{2} \times 7.26 \times {2}^{2} \\ = 2 \times 7.26[/tex]
We have the final answer as
14.52 JHope this helps you
Which of the following is NOT part of a circuit?
a. rim
b.conductor
c.power source
d.load
A car has a speed of 2 m/s and a mass of 1500kg. What is the car’s kinetic energy
Answer:
3,000 m/s
Explanation:
3,000 m/s
Examine the weather map.
A weather map of the United notes. The following are shown on the map: major cities with high and low temperatures; high and low pressure systems; types of precipitation, fronts. The arrow is pointing to an H in a circle.
What does the symbol indicated by the arrows most likely represent?
a hurricane
low pressure
high pressure
high temperatures
Answer:
High pressure.
Explanation:
The symbol H indicates high pressure, while the symbol L indicates low pressure. Therefore, option C is correct.
What is a weather map?A weather map is a map of the world or a portion of it that uses symbols to depict the weather conditions at a given time, including temperature, pressure, wind speed and direction, humidity, clouds, visibility, and type and amount of precipitation.
Different kinds of weather maps are used by meteorologists to display forecasts. Satellite, Doppler radar, precipitation, temperature, and wind speed are the primary weather maps. Let's investigate each of these in greater depth. There are four types of weather maps and that is station model map, aviation map, temperature map, and streamline map.
The symbol H indicates high pressure. Therefore, option C is correct.
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20. A cannon shoots a ball at 38 m/s at an angle of 30°. Ignore the original height of the cannon and assume level ground.
a.How long is the cannon ball in the air?
b. How far does the cannon ball travel?
c.What is the maximum height of the cannon ball?
Mechanical weathering is also called ______weathering
Answer:
physical
Explanation:
physical weathering and disaggregation, causes rocks to crumble. Water, in either liquid or solid form, is often a key agent of mechanical weathering. For instance, liquid water can seep into cracks and crevices in rock.
why do the stars appear like pointed objects
Answer:
because of where we are and our distance away from them, in reality they're giant balls of burning gas, like the sun. some stars are even bigger than the sun
Explanation:
calculate the densities of the following materials. Material A has a volume of 2 cm 3 and mass of 30 g.
Answer:
0.015kgcm^3
Explanation:
density = mass / volume
density = (30/1000) / 2
= 0.015kgcm^3
Anyone please help me with this ???I need help with question a,c,d, and e ???ASAP 12 points
An airplane accelerates down a runway at 3.20 ms for 32.8 seconds until it finally lifts off the ground determine the distance traveled before takeoff
Answer:
105 meters.
Explanation:
If the airplane moves with the speed of 3.20 m/s for 32.8 seconds on the ground before takeoff, it covers 105 meters distance on the ground. We can calculate the distance by using the formula of speed which is speed is equal to distance divided by total time taken. We have to remove time present below the distance so for that we have to cross multiply and we get distance equal to speed x time. So by putting the values of speed and time we get our answer.
i need help on this 8th grade knowledge please
Help thank you...............
Answer:
do explain what u need help with?
It takes me 12s to lift a box upward with 20 N of force to a height of 45m. What was my power output ?
Answer:
75Watts
Explanation:
Given parameters:
Time = 12s
Force applied = 20N
Height = 45m
Unknown:
Power output = ?
Solution:
Power is defined as the rate at which work is done.
It is mathematically expressed as;
Power = [tex]\frac{work done}{time}[/tex]
Work done = force x distance = 20 x 45 = 900J
Power = [tex]\frac{900}{12}[/tex] = 75Watts
A 2 kg object is a distance of 10,000,000 m away from the center of Earth, which has a mass of nearly 6×1024 kg. What is the approximate gravitational field strength of Earth’s gravitational field at the location of the 10 kg object?
A2 N/kg
B 4 N/kg
C 10 N/kg
D The gravitational field strength is negligible and, therefore, approximately zero.
Answer:
4 (N/kg) or B
Explanation:
An application of the equation for Newton’s law of universal gravitation can be used to determine the gravitational field strength at the 2 kg object’s location.
The approximate gravitational field strength of Earth’s gravitational field at the location of the 10 kg object is 4.00 N/kg. Hence, option (B) is correct.
Given data:
The mass of object is, [tex]m = 2\;\rm kg[/tex].
The distance of object from Earth is, [tex]d=10,000,000\;\rm m[/tex].
The mass of Earth is, [tex]M=6 \times 10^{24} \;\rm kg[/tex].
The expression for the gravitational field strength of Earth is,
[tex]g = \dfrac{GM}{d^{2}}[/tex]
Here, G is the universal gravitational constant and its standard value is [tex]6.67\times10 ^{-11} \;\rm Nm^{2}/kg^{2}[/tex].
Solve by substituting the values as,
[tex]g = \dfrac{6.67 \times 10^{-11} \times 6 \times 10^{24}}{(10,000,000)^{2}}\\g \approx 4.00 \;\rm N/kg[/tex]
Thus, we can conclude that approximate value of gravitational field strength of Earth at the location of object is 4.00 N/kg. And option (B) is correct.
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At what point or points of the swing is your kinetic energy the least?
Kinetic energy is least at the both at the lowest point and at the top of the swing when you are still for a moment at the highest point just before falling again.
Kinetic energy is least at the top of the swing when you are still for a moment at the highest point just before falling again.
Kinetic energy is least as you are moving from the highest point of the swing moving down to the lowest point of the swing.
Kinetic energy is least at the lowest point at the bottom of the swing.
Answer:
The correct option is;
Kinetic energy is least as you are moving from he highest point of the swing moving down to the lowest point of the swing
Explanation:
The formula for the kinetic energy, KE, is given by the following formula;
KE = 1/2 × m × v²
Where;
m = The mass of the body in the study
v = The velocity of motion of the body
Therefore, the kinetic energy increases with velocity and therefore, is lowest at the top of the swing when the object is still for a moment
The total mechanical energy of the body is given by the following equation;
Total mechanical energy, [tex]E_T[/tex] = PE + KE = Constant
Where;
PE = The potential energy of the body = Mass × Acceleration due to gravity × Height
Therefore, the potential energy is highest at the top of the motion and lowest at the lowest point, which gives;
The kinetic energy is lowest at the top of the motion and highest at the lowest point of the motion.
At one focus of the ellipse of a planet’s orbit is the _______ and the other focus has nothing.
Restaurant owners agree to comply with state, but not federal, health
regulations when applying for a public health license. true or false
Answer:
False.
Explanation:
A public health license can be defined as series of privileges and authority granted to a practitioner in the public domain, to offer services to the general public after admitting to comply with the standards, rules and regulations set aside by health regulatory agencies and the government (both state and federal).
This ultimately implies that, all restaurant owners must have met the minimum requirements (criteria) and agree to comply with all the standards, rules and regulations with respect to public health before they are endorsed and then given a license to practice or operate by the appropriate agency or authorities.
Hence, restaurant owners agree to comply with state, federal, and health regulations when applying for a public health license.
Students want to build a simple motor to demonstrate the relationship between magnetism and electricity. Each student group has a wooden block, paper clips, a battery, and some copper wire. What additional material is necessary to build a simple motor?
A.
An iron nail is necessary to produce a temporary magnetic field.
B.
A magnet is necessary to produce a permanent magnetic field.
C.
An iron nail is necessary to act as the electrical circuit load.
D.
A magnet is necessary to act as the electrical circuit load.
Answer:
B. A magnet is necessary to produce a permanent magnetic field.
Explanation:
When building a simple motor, a permanent magnet is necessary to produce a magnetic field in which opposite North South polarity which will help in rotating the main copper core when the battery is connected.
A student connects four AA batteries (1.5 V each) in series to light up a light bulb. The circuit has a resistance of 35 2. How much current
flows through the circuit? (AKS 10a)
A.47 A
B. 5.83 A
C.25 A
D.17 A
Answer:
D
Explanation:
6/35=0.17
If you shake one end of a rope up and down , a wave passes through the rope. Which type of wave is it?
Answer: a transverse wave
Explanation:
Answer:
a transverse wave
Explanation:
I think
A player throws a javelin at an unknown angle with a horizontal velocity 20 m/s and vertical velocity 60 m/s. Find its angle and resultant velocity.
Answer:
63º~64º
Explanation:
so imagine a graphic with a triangle. The distance between the zero and the horizontal (x) is 20 and the distance between 0 and vertical (y) is 60
20 = base
60 = height
hypotenuse = L
tg = cato/cata
tg = 60/20
tg = 2
I give up
After a storm, a hospital may have to rely on backup generators to power some equipment. Which is the energy conversion provided by the generators?
A. mechanical to electrical energy
B. thermal to mechanical energy
C. nuclear to mechanical energy
D. thermal to electric energy
Answer:
in a generator mechanical energy is a device that converts a form of energy into electricty
The energy conversion provided by the generators is: mechanical to electrical energy. Hence, option (A) is correct.
What is working principle of electric generators?An electric generator is a device that generates electric energy, which can either be immediately delivered to houses, businesses, and other structures or stored in batteries. Electromagnetic induction is the basis for how electric generators operate.
A horseshoe-shaped magnet's poles are quickly rotated around a conductor coil, which is a copper coil that has been tightly wound onto a metal core. An armature is made up of a conductor coil and a core. The armature is rotated by a mechanical energy source, such as a motor, by means of a shaft connection.
The magnetic field that exists between the magnet's two poles is broken off when the coil turns. The conductor's electrons will interact with the magnetic field, causing an electric current to flow through it.
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Two skaters stand facing each other. One skater's mass is 60 kg, and the other's
mass is 75 kg. The two skaters push off each other. After the push, the smaller
skater has a velocity of 3.0 m/s. If no other forces are acting on the skaters, what
is the velocity of the larger skater?
Answer:
v' = 2.4 m/s
Explanation:
Given that,
Mass of one skater, m = 60 kg
Mass of the other's skater, m' = 60 kg
The two skaters push off each other. After the push, the smaller skater has a velocity of 3.0 m/s.
When there is no external force acting on a system, the momentum remains conserved. It means initial momentum is equal to the final momentum. Let v' is the velocity of the larger skater.
mv = m'v'
[tex]v'=\dfrac{mv}{m'}\\\\v'=\dfrac{60\times 3}{75}\\\\v'=2.4\ m/s[/tex]
So, the velocity of the larger skater is 2.4 m/s.
If the pH of a substance is 12.4, the substance is a _______
- strong acid
- weak acid
- strong base
- weak base
Answer:
Strong base
Explanation:
A strong base usually has the pH of between 12 to 14
If the pH of a solution is 12.4, the substance is called a Strong base. Hence, option C is correct.
What are acids and bases?When a substance is dissolved in water, H⁺ hydrogen ions are formed. These substances are called Acids. H⁺ ions are positive ions and hence, they donate protons to other substances.
When a substance is dissolved in water, OH⁻ hydroxyl ions are formed. These substances are called Bases. OH⁻ ions are negative ions that are capable of accepting the protons/hydrogen ions.
Acids are substances having more hydrogen ions than hydroxyl ions and it has a sour taste. Bases are substances having more hydroxyl ions than hydrogen ions and it has a bitter taste.
The acids and bases are differentiated by using the pH scale. pH represents the potential of hydrogen which measures the hydrogen and hydroxyl ions. It is a negative logarithm of H⁺ ion concentration.
The pH scale ranges from 0-14. The neutral power in the pH scale is 7 and the water shows the neutral range. If pH shows less than 7 it is an acidic solution and litmus paper turns red.
If pH shows greater than 7, it is a base or alkaline solution and the litmus paper turns blue. Weak bases range from 7.3-10. Strong bases range from 10-14.
Hence, the pH shows 12.4, which represents a strong base. Thus, the correct solution is C.
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25 points! Will give brainliest!
1. Draw the diagram
2. List the Givens
3. Select the correct equation to solve for and manipulate the equation
4. Substitute the given values
A ball is thrown horizontally from the roof of a building 60 m tall with a speed of 6.9 m/s.
a.How much later does the ball hit the ground?
b. How far from the building will it land?
c. What is the velocity of the ball just before it hits the ground?
Answer:
B my brother say that it was
The projectile launcher shown below will give the object on the right an initial horizontal speed of 5.9 m/s. While the other object will be dropped with no initial speed. The objects are initially 179 cm above the ground and separated by 142 cm. What will be the difference in the landing locations of the two objects?
Answer:
104.3 cm or 179.7
Explanation:
First find time that it takes for the object to hit the ground
[tex]\sqrt{(2H)/g} -> \sqrt{(2 x 179)/ 9.8} = 6.04s\\[/tex]*
Then find xf of projectile [tex]xf= 5.9(6.04) = 37.7\\\\[/tex]
not 100% sure if the projectile is going away from the object or towards it but you either do 142- 37.7 or 142+37.7
hope that helps
"217 cm" would be the difference throughout the landing locations of the two objects.
Given:
Initial horizontal speed,
v = 5.9 m/sHeight,
h = 179 cmBy applying equation of motion, we get
→ [tex]S = ut+\frac{1}{2}at^2[/tex]
By substituting the values, we get
→ [tex]179\times 10^{-2}=0+\frac{1}{2}\times 9.8\times t^2[/tex]
→ [tex]3.58= 9.8t^2[/tex]
[tex]t^2 =\frac{3.58}{9.8}[/tex]
[tex]t = \sqrt{0.36531}[/tex]
[tex]= 0.61 \ s[/tex]
now,
The horizontal distance travelled by the first particle will be:
→ [tex]d = v\times t[/tex]
[tex]= 5.9\times 0.61[/tex]
[tex]= 3.59 \ m[/tex]
or,
[tex]= 359 \ cm[/tex]
hence,
The distance between particle will be:
= [tex]d -142[/tex]
= [tex]359-142[/tex]
= [tex]217 \ cm[/tex]
Thus the above approach is right.
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Which could be an example of a balanced force?
An asteroid moving at a constant speed through space
A box of dishes falling from a counter
A rocket taking off
O A car accelerating from a stop sign
Answer:
An asteroid moving at a constant speed through space.
Explanation:
An example of a balanced force is; an asteroid moving at a constant speed through space.
A balanced force is a force that does not produce acceleration or cause motion of a stationary body. According to Newtons first law, a body continues in its state of rest or uniform motion unless it is acted upon by an unbalanced force.
The asteroid is moving at constant velocity because all the forces that act on it are balanced. Once it is acted upon by unbalanced forces, it will accelerate in obedience to Newton's first law.
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