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A level physics help

What is the answer to this question. I think its D but, could be wrong. Can anyone tell meSmartSelect_20211130-183309_Chrome.jpg
(edited 2 years ago)
Original post by Elderfury843
What is the answer to this question. I think its D but, could be wrong. Can anyone tell meSmartSelect_20211130-183309_Chrome.jpg

It can't be D, because at maximum height, the ball is at rest.
If the ball is at rest there is no drag force.
The drag force is zero but the ball has weight, so they can't be equal.
Original post by Stonebridge
It can't be D, because at maximum height, the ball is at rest.
If the ball is at rest there is no drag force.
The drag force is zero but the ball has weight, so they can't be equal.

The ball is not at rest as there is still horizontal motion so there still is kinetic energy
Original post by Elderfury843
The ball is not at rest as there is still horizontal motion so there still is kinetic energy

Maximum height.
Ball is at rest- not moving once it instantaneously hits the maximum.
Thus drag is zero- weight doesnt vanish.
Original post by Elderfury843
The ball is not at rest as there is still horizontal motion so there still is kinetic energy

There is no horizontal motion. Read the question. It says the motion is vertical.
Original post by Stonebridge
There is no horizontal motion. Read the question. It says the motion is vertical.

So, what do you think is
Original post by Elderfury843
So, what do you think is

Use a process of elimination.
If the ball is at rest and the drag is zero, (we agreed this when eliminating D) that rules out another of the answers doesn't it, leaving just 2.
Also, the force of the racket on the ball, F, only occurs on impact and gives the initial motion. After that, it's gone.
That rules out another of the options.
Now you tell me, what do you think it is? There's only one left.
Original post by Stonebridge
Use a process of elimination.
If the ball is at rest and the drag is zero, (we agreed this when eliminating D) that rules out another of the answers doesn't it, leaving just 2.
Also, the force of the racket on the ball, F, only occurs on impact and gives the initial motion. After that, it's gone.
That rules out another of the options.
Now you tell me, what do you think it is? There's only one left.

Would it be A
Original post by Elderfury843
Would it be A

Yes that's it. :smile:
The acceleration due to gravity always acts in a downwards direction - it's in the same direction as the force that causes it - the weight of the ball.
Even at the highest point when the ball is instantaneously at rest, the force is still acting. And, although it can seems odd, the ball still has a downwards acceleration. It has had this all the time during the motion. It slows it down as it rises, and speeds it up as it falls. It doesn't stop at the maximum height and the earth is still pulling it downwards at that point. The weight of the ball, the earth's pull on it, doesn't suddenly stop.
Original post by Stonebridge
Yes that's it. :smile:
The acceleration due to gravity always acts in a downwards direction - it's in the same direction as the force that causes it - the weight of the ball.
Even at the highest point when the ball is instantaneously at rest, the force is still acting. And, although it can seems odd, the ball still has a downwards acceleration. It has had this all the time during the motion. It slows it down as it rises, and speeds it up as it falls. It doesn't stop at the maximum height and the earth is still pulling it downwards at that point. The weight of the ball, the earth's pull on it, doesn't suddenly stop.

Thanks for the help
Original post by Elderfury843
What is the answer to this question. I think its D but, could be wrong. Can anyone tell meSmartSelect_20211130-183309_Chrome.jpg

its A also does anyone have ial physics unit 4 mark scheme oct 2021? in exchange with p3.p4 and s2

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