A rocket, which is in deep space and initially at rest relative to an inertial reference frame, has a mass of 50.2 × 105 kg, of which 12.5 × 105 kg is fuel. The rocket engine is then fired for 450 s, during which fuel is consumed at the rate of 370 kg/s. The speed of the exhaust products relative to the rocket is 4.90 km/s. (a) What is the rocket's thrust? After the 450 s firing, what are (b) the mass and (c) the speed of the rocket?

Astone is thrown with a speed v0 and returns to earth, as the drawing shows. ignore friction and air resistance, and consider the initial and final locations of the stone. which one of the following correctly describes the change δpe in the gravitational potential energy and the change δke in the kinetic energy of the stone as it moves from its initial to its final location? options a.δpe = 0 j and δke = 0 j b.δpe is positive and δke is negative c.δpe = 0 j and δke is positive d.δpe is negative and δke is positive e.δpe = 0 j and δke is negative