Two ice skaters, daniel (mass 65 kg) and rebecca (mass 45 kg), are practicing. daniel is intially at rest when struck by rebecca moving at 13 m/s. after the collision, rebecca has a velocity of 8 m/s at an angle of 53.1º from her initial direction. a) what are the magnitude and direction of daniel’s velocity after the collision? b) what is the change in kinetic energy of the two skaters as a result of the collision?

In a system, when potential energy decreases, then entropy also decreases. true false

The field between two charged parallel plates is kept constant. if the two plates are brought closer together, the potential difference between the two plates either a) decrease b) does not change c) increase?

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.