Balls a, with a mass of 20 kg, is moving to the right at 20 m/s. at what velocity should ball b, with a mass of 40 kg, move so that they both come to standstill upon collision?

Complete the sentence to describe the law of conservation of energy. the law of conservation of energy states that energy cannot be created or , but it can be

What makes thermal imaging cameras useful? they can detect differences in color. they can detect differences in wave speeds. they can detect differences in temperature. they can detect mechanical waves.

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.