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Maths mechanics

Heixi

I’ll post the question and my working out but idk how to get further

It’s question 5

Youve over complicated it. Just think about the answer.
What suvat equation(s) can you use based on the property about the maximum vertical height?
Also make sure you get the displacement correct.

(edited 2 years ago)

Reply 3

Heixi

Original post by mqb2766

Youve over complicated it. Just think about the answer.
What suvat equation(s) can you use based on the property about the maximum vertical height?
Also make sure you get the displacement correct.

Then is the displacement just 2.8m?
Would I use s=Ut +1/2at^2 rearranged for U ?
I’ve got my horizontal and vertical the wrong way round

(edited 2 years ago)

Reply 4

mqb2766

Original post by Heixi

Then is the displacement just 2.8m?
Would I use s=Ut +1/2at^2 rearranged for U ?

There is no reference to time in the question part, so no.
The ball reaches a height of 2.8 above the ground. So the displacement is ....
You've drawn a diagram which is good, but you've incorrectly marked on the maximum height.

Reply 5

Heixi

Original post by mqb2766

Then 2.8-2.5=0.3m?
It says above the ground so I assumed 2.8m above the point

Reply 6

mqb2766

Original post by Heixi

Then 2.8-2.5=0.3m?
It says above the ground so I assumed 2.8m above the point

Yes. The initial point is 2.5 above the ground, so the vertical dispacement from the initial point is 0.3.

(edited 2 years ago)

Reply 7

Heixi

Original post by mqb2766

Yes. The initial point is 2.5 above the ground, so the vertical dispacement from the initial point is 0.3.

So I would use v^2=U^2+2as vertically
but isn’t U at max height =0

Reply 8

mqb2766

Original post by Heixi

So I would use v^2=U^2+2as vertically
but isn’t U at max height =0

No, U = ... is what you have to show.
However, you've almost got the right idea ...

(edited 2 years ago)

Reply 9

Heixi

I got 3/5=gt^2
I need to either sub something into t or use another equation

Reply 10

mqb2766

Original post by Heixi

I got 3/5=gt^2
I need to either sub something into t or use another equation

Its not that suvat equation as time is not involved in this question part.
Your previous post had the right suvat equation to use for vertical motion.

Reply 11

Heixi

Original post by mqb2766

Its not that suvat equation as time is not involved in this question part.
Your previous post had the right suvat equation to use for vertical motion.