Wheel revolution problem

[Leah5467]

Hi,this is my question:

The answer says identify symmetry,what is symmetry?

Thank you!

 

[Harry_the_cat]

Can you please show Part (a) of this question to put it in context?

 

[Leah5467]

This is the part a:

Thank you!

 

[Harry_the_cat]

Ok. The wheel is rotating at a constant rate. It takes 10 min for P to reach the top height of 100 metres. The table tells us that after 2 min, P is 9.5 metres high. Can you see that after 8 min (ie 2 minutes bevore it is at the top), P will be 9.5 m down from the highest level of 100 metres. So h(8) = 100 - 9.5 = 90.5 metres.
That's what it means by symmetry.
Can you see how they got b(ii)?

 

[Leah5467]

Ohh i see! Thank you!