An ice sled powered by a rocket engine starts from rest on a large frozen lake and accelerates at 12.8 m/s2 . at t1 the rocket engine is shut down and the sled moves with constant velocity v for another t2 s. the total distance traveled by the sled is 5.37 × 103 m and the total time is 97.7 s. find t1.

To do work, this truck uses energy stored in chemical fuel and an electrical battery. how much total energy does this truck put out?

Do you agree with scientist’s prediction about the warming of alaska and other polar regions?

Aperson gives a shopping cart an initial push along a horizontal floor to get it moving, and then lets go. the cart travels forward along the floor, gradually slowing as it moves. consider the horizontal force(s) on the cart while it is moving forward and slowing. which of the following statements is correct? (a) both a forward and a backward force are acting on the cart, but the forward force is larger. (b) only a forward force is acting which diminishes with time. (c) both a forward and a backward force are acting on the cart, but the backward force is larger. (d) only a backward force is acting, no forward force.