Q. A runner of mass 51.0 kg runs around the edge of a horizontal turntable mounted on a vertical, frictionless axis through its center. The runner's velocity relative to the earth has magnitude 3.50 m/s. The turntable is rotating in the opposite direction.
Q. A wooden block with mass 1.55 is placed against a compressed spring at the bottom of a slope inclined at an angle of 30.0 (point A). When the spring is released, it projects the block up the incline. At point B, a distance of 7.50 up the incline from , the block is moving up the incline at a speed of 5.60 and is no longer in contact with the spring. The coefficient of kinetic friction between the block and incline is 0.50. The mass of the spring is negligible.
Calculate the amount of potential energy that was initially stored in the spring.