In a closed system that has 560 J of mechanical energy, the gravitational potential energy of a weight being lowered by a pulley decreases from 250 J
to 175 J. How does the system's kinetic energy change if there is no friction??
O A. It increases from 560 J to 735 J.
O B. It decreases from 385 J to 310 J.
O C. It decreases from 560 J to 485 J.
D. It increases from 310 J to 385 J.

Suppose while hauling rocks, you accidentally drop one. it breaks apart in flat, planar sections. what type of rock did you just drop? 20 points

How many neutrons does plutonium -196 with an atomic number of 78.

Visualize the problem and identify special cases first examine the problem by drawing a picture and visualizing the motion. apply newton's 2nd law, ∑f⃗ =ma⃗ , to each body in your mind. don't worry about which quantities are given. think about the forces on each body: how are these consistent with the direction of the acceleration for that body? can you think of any special cases that you can solve quickly now and use to test your understanding later? one special case in this problem is if m2=0, in which case block 1 would simply fall freely under the acceleration of gravity: a⃗ 1=−gj^.