Using energy considerations, calculate the average force (in N) a 63.0 kg sprinter exerts backward on the track to accelerate from 2.00 to 7.00 m/s in a distance of 25.0 m, if he encounters a headwind that exerts an average force of 30.0 N against him.

An applied force of 14.4 N acts on a 2.50 kg mass that is initiallyt at rest. over a distance 2.09 m the object changes its kinetic energy by 19.3 j. what is the coefficient of kinetic friction?

A 5.22-kg object passes through the origin at time t = 0 such that its x component of velocity is 5.40 m/s and its y component of velocity is -3.03 m/s. (a) What is the kinetic energy of the object at this time? (b) At a later time t = 2.00 s, the particle is located at x = 8.50 m and y = 5.00 m. What constant force acted on the object during this time interval? magnitude N direction ° measured from the +x axis (c) What is the speed of the particle at t = 2.00 s? m/s

Tarzan (80 kg) drops from a height of 2.5 m to swing down and pick up Jane.  If he picks up Jane (60 kg) with an inelastic collision, determine the following. The velocity just before picking up Jane. (7.1 m/s) The velocity just after picking up Jane.  (4.04 m/s) The percentage of energy lost when picking up Jane.  (43%) The height (h), after picking up Jane.  (0.82 m)