How much power does it take to do 400 joules of work in 5 seconds?

Is the alien theory a scientific claim? why or why not? just took the test it was , : " the alien theory is not a scientific claim because it is not based on valid data, there is no evidence to support it, and it does not come from a reliable source."

The momentum of an isolated system is conserved a) only in inelastic collisions. b) only in elastic collisions. c) in both elastic and inelastic collisions

Within a pendulum, as potential energy decreases, energy increases. a. heat b. kinetic c. frictional d. gravitational