stuck on this question

I'm not sure how to calculate the amplitude to find the velocity for biii image-cf1f5cf6-fbab-4c98-8b17-10288a76dd458401102683160664720-compressed.jpg.jpeg

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Reply 1

Joinedup

It's a one marker - I think they're just expecting you to rearrange Ek=1/2 mv² and use the maximum kinetic energy you found in the previous section

Reply 2

Eimmanuel

Study Forum Helper

Original post by alithealien

I'm not sure how to calculate the amplitude to find the velocity for biii image-cf1f5cf6-fbab-4c98-8b17-10288a76dd458401102683160664720-compressed.jpg.jpeg

Joinedup had suggested the method that this question expects you to solve for maximum speed but if you still want to know how to find the “amplitude”, see below.

The “amplitude” can be obtained using Pythagoras’s theorem. When the girl is raised to 250 mm above its lowest position, imagine there is a right-angled triangle, with the hypo side as the distance you calculated in (i) and the horizontal side as the “amplitude” you want to find.

However, the “amplitude” may only help you get the max speed “approximately”.