A 20 g ping pong ball is thrown so that it gains a velocity v = 2.0 m/s x^ +4.0 m/s y^ +3.0 m/s z^. What is the kinetic energy gained by the ball?

What does the law of conservation of mass state?

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^.

Anika asks eva to roll a basketball and then a bowling ball to her. which requires more force to roll, and why?