1. A 12 kg dog is running 5 m/s. How much kinetic energy does the dog have? 2. Another dog is also running at 5 m/s, but this one has 100 Joules of kinetic energy. What is this dog's mass?

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j ?

Copper has free electrons per cubic meter. a 71.0-cm length of 12-gauge copper wire that is 2.05 mm in diameter carries 4.85 a of current. (a) how much time does it take for an electron to travel the length of the wire? (b) repeat part (a) for 6-gauge copper wire (diameter 4.12 mm) of the same length that carries the same current. (c) generally speaking, how does changing the diameter of a wire that carries a given amount of current affect the drift velocity of the electrons in the wire?

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity