This is an original exam question by Prof Kay Han. It is forbidden to photograph, upload, download, copy, or share this problem with anyone, or to post it to any website.   A kg grand piano was hoisted up onto a 10th floor room in a building.    When the string is m, the string got stuck and the piano started dangling.  The gravity of earth is 9.8 m/s2.  Calculate the period of the dangling piano.  

This is an original exam question by Prof Kay Han. It is forbidden to photograph, upload, download, copy, or share this problem with anyone, or to post it to any website.   A baseball player catches the ball with the glove.  If we way that the action force is “the impact of the ball against the glove”.  The reaction force is

This is an original exam question by Prof Kay Han. It is forbidden to photograph, upload, download, copy, or share this problem with anyone, or to post it to any website.   Little John (in Robinhood) shoots an arrow upward.  As the arrow flies upward, which direction will Little John move?

This is an original exam question by Prof Kay Han.  It is forbidden to photograph, upload, download, copy or share this problem with anyone, or to post it onto any website.   A roller coaster traveling on a track as shown below. Disregard rotational motion and air resistance.  When the cart is at point E ,

This is an original exam question by Prof Kay Han. It is forbidden to photograph, upload, download, copy, or share this problem with anyone, or to post it to any website. A few objects rolling down a wedge with a height H, as shown below.  The all have the radius R and the same mass M, except indicated by small (< R, < M) or large (> R, > M).  Select the last one that will arrive at the bottom.

This is an original exam question by Prof Kay Han. It is forbidden to photograph, upload, download, copy, or share this problem with anyone, or to post it to any website.   Where is the center of Mass of the following item?  The black dot represents the location of the center of mass.

This is an original exam question by Prof Kay Han. It is forbidden to photograph, upload, download, copy, or share this problem with anyone, or to post it to any website. A few objects rolling down a wedge with a height H, as shown below.  The all have the radius R and the same mass M, except indicated by small (< R, < M) or large (> R, > M).  Select the one that will first arrive at the bottom.

This is an original exam question by Prof Kay Han. It is forbidden to photograph, upload, download, copy, or share this problem with anyone, or to post it to any website.   Jill pushes a shopping cart full of groceries with 200 N of force.  To push a shopping cart with half the mass, how fast will the acceleration be comparing with the first case?

This is an original exam question by Prof Kay Han.  It is forbidden to photograph, upload, download, copy or share this problem with anyone, or to post it onto any website.   A skateboarder with a mass of kg at a skate park rides along the path shown in the following figure. If the speed of the skateboarder at point A is  m/s and the height of the ramp is m.  If the height in point B is m, what is her speed in m/s at point B?  Assume that friction is negligible.  

This is an original exam question by Prof Kay Han.  It is forbidden to photograph, upload, download, copy or share this problem with anyone, or to post it onto any website.   A 45 kg hockey player standing at the center of a frictionless ice rink.  He hits a 30 g puck with great force, so that it moves with a speed of 150 m/s to the edge of the rink.  What happens to the hockey player?