Question

1 A ball is thrown vertically upwards. It rises to a maximum height X where it is momentarily at
rest. It then falls downwards.
Which statement is true about the ball’s acceleration? [1]
A The acceleration of the ball is always in the same direction as its velocity.
B The acceleration of the ball is always in the opposite direction to its velocity.
C The acceleration of the ball is downwards at all points including X.
D The acceleration of the ball is zero at X.

can someone explain why the answer is C not A ?

Answer 1

Ok, the answer is C because the force of gravity pulls the ball down at all times, at no point is gravity not pulling the ball down. When you throw the ball upwards with an initial force, it has some speed. When you release the ball, the speed starts at a maximum and there in after looses that speed until it reaches its maximum point at X. The reason why it looses the speed is because the acceleration is always downward (against the upward motion of the ball when it is initially thrown up). If this was not the case, the ball would just speed away and never return. The important thing to consider in part A is the direction of the velocity.When you throw the ball up, the velocity has a direction value, it can be defined as positive or negative it really doesn't matter. The thing that matters most is the acceleration always acts downwards, so when your ball is flying upwards, the velocity is opposite to the acceleration due to gravity. When it falls back down it's in the same direction. Hence why the answer is C and not A. Hope this helps, bit of long winded reply I know!

Answer 2

Perfect !. Thank you so mucccch <3