AP Physics help!!!

Test Preparation AP Test Preparation
1

<p>A 25 kg child on a 2.0m long swing is released from rest when the swing supports make an angle of 30 degrees with the vertical:</p>

<p>a) What is the maximum potential energy that the child has?</p>

<p>b)Disregarding friction, find the child's speed at the lowest point</p>

<p>c) What is the child's total mechanical energy?</p>

<p>d) if the speed of the child at the lowest position is 2.00 m/s what is mechanical energy lost due to friction?</p>

<p>This is my exam review and I have no clue how to do this</p>

2

<p>a. Draw a right triangle with the right angle at the bottom and the 30 degree angle at the top. The hypotunuse is 2.0m. Find the side opposite the 60degree angle and subtract that from 2 to get your height. How do you calculate p.e. from that? (I know, I’m asking you.)
b. Well, at the lowest point, kinetic energy = initial potential energy
c. potential plus kinetic? Conservation of energy so same answer as a.
d. Work non conservative + PE initial = Kinetic energy final</p>

<p>That should help you.</p>