A toy rocket, of mass 0.12 kg, achieves a velocity of 40m/safter 3.0s, when fired straight up. What average thrust force doesthe rocket engine exert?(P.s. I got 1.6N but they told me it's 2.8N help me outhere)(and one more problem thanks)A car of mass m, traveling with a velocity v, strikes a parkedstation wagon,w ho's mass is 2m. The bumpers lock together in hthishead on inelastic collision. Whatfraction fo the initial kineticenergy is lost in this collision?The answer is 2/3, but can someone explain to me why?