Suppose you are helping a friend move. The friend asks you to stand in the back of the pickup truck to hold a piano because there is no rope available to tie it down. Explain why you should refuse this request.

Rosa records the distance that a toy car rolls and the time it takes to cover the distance. what scientific practice is this? collecting data asking a question providing explanations communicating results

Atomic nuclei of almost all elements consist of

Amoving electron has kinetic energy k1. after a net amount of work w has been done on it, the electron is moving one-quarter as fast in the opposite direction. (a) find w in terms of k1. (b) does your answer depend on the final direction of the electron's motion?