Three children are riding on the edge of a merry‑go‑round that has a mass of 105 kg105 kg and a radius of 1.80 m1.80 m . the merry‑go‑round is spinning at 16.0 rpm.16.0 rpm. the children have masses of 22.0,22.0, 28.0,28.0, and 33.0 kg.33.0 kg. if the 28.0 kg28.0 kg child moves to the center of the merry‑go‑round, what is the new angular velocity in revolutions per minute? ignore friction, and assume that the merry‑go‑round can be treated as a solid disk and the children as point masses.

Abatter hits the baseball a with an initial velocity of v0 = 110 ft/sec directly toward fielder b at an angle of 23° to the horizontal; the initial position of the ball is 2.2 ft above ground level. fielder b requires 0.44 sec to judge where the ball should be caught and begins moving to that position with constant speed. because of great experience, fielder b chooses his running speed so that he arrives at the “catch position” simultaneously with the baseball. the catch position is the field location at which the ball altitude is 8.4 ft. determine the velocity of the ball relative to the fielder at the instant the catch is made.

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e

When you hold a rectangular object, how does the area of the side that is resting on your hand affect the pressure and the force that the object exerts?