Q1. A student removes a 10.50 kg stereo from a shelf that is 1.802 m high. The amplifier is lowered at a constant speed to a height of 0.75 m. What is the work done by a) person and b) gravitational force that acts on the amplifier?
Q2. A 0.012 kg marble sliding to the right at 27.5 cm/s on a frictionless surface makes an elastic head-on collision with a 0.014 kg marble moving to the left at 21.8 cm/s. After the collision, ?rst marble moves to the left at 21.8 cm/s. find the velocity of the second marble after the collision. Reply in units of m/s