Question 4 5 pts A 1.51 kg mass is sliding across the level ground with an initial velocity of 4.3 m/s. What is the coefficient of kinetic friction if the mass to comes to rest over a distance of 2.47 m? Assume that only friction is affecting the object's motion. (Think work and energy!)Question 7 5 pts A constant applied force of 48.3 N j lifts an object straight up a distance of 2.53 m. If the change is gravitational potential energy is 73.6 J, what is the object's change in kinetic energy?Question 8 5 pts A 0.21 kg mass is held at rest against a compressed spring with a spring constant of 200 N/m. When released, the mass leaves the spring with a speed of 6.07 m/s. Assuming that the spring force is wholly responsible for changing the motion of the mass, by what distance was the spring initially compressed from its equilibrium position?Question 9 5 pts A 0.26 kg mass is held against a compressed spring with a spring constant of 2,944 N/m. The mass is initially at rest upon a horizontal surface and the spring force is directed parallel to the plane of the surface. If the coefficient of kinetic friction is 0.651, with what speed does the mass leave contact with the spring if the spring is initially compressed by 0.05 m