A student holds a 2.0 kg air rifle, un-braced with a very loose grip. The muzzle velocity of a 2.0 g bullet fired from the rifle is about 140 m/s. What is the recoil speed of the gun? What could the student do to reduce the recoil speed of the air rifle? Explain.​

Estimate the kinetic energy of the neptune with respect to the sun as the sum of the terms, that due to its daily rotation about its axis, and that due to its yearly revolution about the sun. [assume the neptune is a uniform sphere with mass = 1.0×1026 kg , radius = 2.5×1010 m , rotation period 16.1 h , orbital period 6.01×104 d and is 4.6×109 km from the sun.]