Evidence for the particle nature of light are not: 1. refraction, 2. many colors of light, 3. diffraction. These are all phenomenon that support wave theory of light. Evidence for particle nature of light is photoelectric effect. Because it was discovered that you need discrete energies of light to eject electrons from a metal surface and not continuous as the wave theory of light suggests.
How much work in J does the string do on the boy if the boy stands still?
<span>answer: None. The equation for work is W = force x distance. Since the boy isn't moving, the distance is zero. Anything times zero is zero </span>
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<span>How much work does the string do on the boy if the boy walks a horizontal distance of 11m away from the kite? </span>
<span>answer: might be a trick question since his direction away from the kite and his velocity weren't noted. Perhaps he just set the string down and walked away 11m from the kite. If he did this, it is the same as the first one...no work was done by the sting on the boy. </span>
<span>If he did walk backwards with no velocity indicated, and held the string and it stayed at 30 deg the answer would be: </span>
<span>4.5N + (boys negative acceleration * mass) = total force1 </span>
<span>work = total force1 x 11 meters </span>
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<span>How much work does the string do on the boy if the boy walks a horizontal distance of 11m toward the kite? </span>
<span>answer: same as above only reversed: </span>
<span>4.5N - (boys negative acceleration * mass) = total force2 </span>
<span>work = total force2 x 11 meters</span>
The work-energy theorem explains the idea that the net work - the total work done by all the forces combined - done on an object is equal to the change in the kinetic energy of the object. After the net force is removed (no more work is being done) the object's total energy is altered as a result of the work that was done.
This idea is expressed in the following equation:
is the total work done
is the change in kinetic energy
is the final kinetic energy
is the initial kinetic energy
mark me as brainliest ❤️
Chiefly in science fiction) an invisible barrier of exerted strength or impetus.
Answer:
32km per hour
Explanation:
Explanation:
In first case v = a t
==> a t = 40 km p h
Now distance covered S1 + S2 + S3
S1 = 1/2 a t^2 and S3 = 1/2 a t^2
But S2 = 3t * 40 = 120 t km
Hence total distance = at^2 + 120 t
Time taken (total) = t + 3t + t = 5 t
Hence average speed = at^2 + 120 t / 5 t
Cancelling t we have at + 120 / 5 = 40 + 120 / 5 = 160/5 = 32 km per hour