Asmall ball of mass 0.64 kg is attached to one end of a 0.840-m-long massless rod, and the other end of the rod is hung from a pivot. when the resulting pendulum is 26° from the vertical, what is the magnitude of the torque about the pivot?

In a game of pool, ball a is moving with a velocity v0 of magnitude v0 = 15 ft/s when it strikes balls b and c, which are at rest and aligned as shown. knowing that after the collision the three balls move in the directions indicated and assuming frictionless surfaces and perfectly elastic impact (that is, conservation of energy), determine the magnitudes of the velocities va, vb, and vc.

If a car is traveling on the highway at a constant velocity, the force that pushes the car forward must be a. equal to the weight of the car. b. less than the force of friction exerted upon the car. c. equal to the force of friction exerted upon the car. d. greater than the weight of the car.

List and describe three ways that humans can change ecosystems and three ways that humans can protect ecosystems.