Two particles, each of mass m, are initially at rest very far apart. obtain an expression for their relative speed of approach at any instant as a function of their separation distance d if the only interaction is their gravitational attraction to each other. express your answer in terms of some or all of the variables m, d, and gravitational constant g.

Write down two additional questions about earth's magnetic field that will make your presentation more informative.

To practice problem-solving strategy 10.1 for energy conservation problems. a sled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slides a distance d1 down the slope and then covers the distance d2 along the horizontal terrain before stopping. find the coefficient of kinetic friction μk between the sled and the ground, assuming that it is constant throughout the trip.

Metals are good conductors of electricity because they