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If the net work done on an object is positive, then the object’s kinetic energy  

A diver who weighs 500 N steps off a diving board that is 10 m above the water. The diver hits the water with kinetic energy of

An ice skater has a moment of inertia of 5.0 kg∙m2 when her arms are outstretched.  At this time she is spinning at 3.0 revolutions per second (rps).  If she pulls in her arms and decreases her moment of inertia to 2.0 kg∙m2, how fast will she be spinning?

On a balanced seesaw, a girl three times as heavy as her partner sits

A bicycle wheel rotates uniformly through 2.0 revolutions in 4.0 s.  What is the frequency of the wheel’s rotation?

Action-reaction forces are

A 2000-kg car, traveling to the right at 30 m/s, collides with a brick wall and comes to rest in 0.20 s.  What is the average force the car exerts on the wall?

A 2-kg object is moving at 3m/s. A 4-N force is applied in the direction of motion and then removed after the object has traveled an additional 5m. The velocity  after the object travels 5 m is:

If you blow up a balloon, and then release it, the balloon will fly away.  This is an illustration of

A pulsar (a rotating neutron star) emits pulses at a frequency of 0.40 kHz.  The period of its rotation is