What makes metals like copper conductive to electricity?

When a resistor with resistance r is connected to a 1.50-v flashlight battery, the resistor consumes 0.0625 w of electrical power. (throughout, assume that each battery has negligible internal resistance.) what power does the resistor consume if it is connected to a 12.6-v car battery? assume that r remains constant when the power consumption changes.

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?

What is the measure of a change in an objects velocity?