Anyone will rate brainless and would a lot

An object moves from the position +34m to the position -15m in 15 seconds. what is it's total displacement? what is it's average velocity?

Which of the following are properties of mechanical waves? check all that apply ⭕️ particles of the medium move back and fourth, but do not move with the wave. ⭕️ the particles of the medium always move parallel to the wave motion. ⭕️ wave motion begins with a disturbance in the medium. ⭕️ waves transport energy from a source outward, away from the source.

All the simple machines make work easier to do by changing the or of a force. a. size; type b. work; type c. size; direction d. type; direction