I beleive she isnt doing any work due to holding the box motionless, you must be exerting a force in the direction of the box motion. If she is just standing there holding the box their isn't no work becuase no distance has been covered. work = force = distance.
If the light from the sun has higher frequencies from one side of the sun than from the other side, it is proof that the Sun is rotating.
Doppler effect states that, if a person is standing still and a source ( sound / light ) is moving towards him, the frequency of the wave emitted from the object will increase and if the source ( sound / light ) is away from him, the frequency of the wave emitted from the object will decrease.
So, if the light from the sun has higher frequencies from one side of the sun than from the other side, it means that the Sun is rotating. The higher frequencies points are the points that rotating towards Earth and lower frequencies points are the points that rotating away from Earth.
Therefore, if the light from the sun has higher frequencies from one side of the sun than from the other side, it is proof that the Sun is rotating.
To know more about Doppler Effect
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To provide a greater certainty that the observed results are not by chance.
Answer:
a) 1.22 s
b) 9.089 m
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.81 m/s²

Time taken by the ball to reach the highest point is 1.22 seconds

The maximum height the ball will reach above the ground is 1.75+7.339 = 9.089 m