Asmall toy cart equipped with a spring bumper rolls toward a wall with a speed of v. the cart rebounds from the wall, with the same speed v. the sketch below shows the initial velocity vector vi , final velocity vector v f, and the initial momentum vector p i. using the initial momentum vector as a basis, draw the change in momentum vector δp for the cart. you can obtain each vector's length and orientation by clicking on it to select it.

Why do astronauts in the space shuttle weigh less?

A58-kg boy swings a baseball bat, which causes a 0.140-kg baseball to move toward third base with a velocity of 38.0 m/s.

Cells in the nervous system have a potential difference of 70 mv across the cell membrane separating the interior of the cell from the extracellular fluid. this potential difference is maintained by ion pumps that move charged ions across the membrane. is this an emf? select the correct answer and explanation. 1)no. the ion pumps cannot separate charges; thus, they cannot create a potential difference. 2)yes. the ion pumps cannot separate charges, but they still can create a potential difference. 3)yes. the ion pumps can actively separate charge; thus, they can create a potential difference. 4)no. the ion pumps can separate charges, but they cannot create a potential difference.