A cream tangerine is thrown directly upward past three evenly spaced windows of equal heights. Rank the windows according to (a) the average speed of the cream tangerine while passing them, (b) the time the cream tangerine takes to pass them, (c) the magnitude of the acceleration of the cream tangerine while passing them, and (d) the change in velocity in the speed of the cream tangerine during the passage, greatest first.

Question

mhchen · Answer

First of all, we should start with (c)
Ignoring friction, there's only 1 thing causing the ball to decelerate, which is force of gravity.
Therefore, the acceleration is the SAME.

(d) Now, if the acceleration is the same, and we know gravity is in the downwards position, and the initial velocity is in the upwards direction, its velocity is decreasing as it goes up.
BUT, since the acceleration is the same, then the velocity changes by the same rate, so the change in velocity is the SAME at all three windows.

(b) Now that we know velocity is decreasing from bottom to top:
It takes more time to pass a window right?
So the time it takes to pass window gets longer by each window.

okdutchman7 · Answer

@mhchen may you please explain why the magnitude of acceleration is the same.

mhchen · Answer

Because the only force acting upon it is gravity. There is no other forces right?