Work needed!

Bruce stands on a bank beside a pond, grasps the end of a 20.0-m-long rope attatched to a nearby tree and swings out to drop into the water.If the rope starts at an angle of 35.0 degrees with the vertical, what is Bruce's speed at the bottom of the swing?

You are on the Moon and would like to send a probe into space so that it does not fall back to the surface of the Moon. What launch speed do you need?

A block of wood is compressed 2.0 nm when inward forces of magnitude 120N are applied to it on two opposite sides. (a) Assuming Hooke's law holds, what is the effective spring constant of the block? (b) Assuming Hooke's las still holds, how much is the sa...

The length of a spring increases by 7.2 cm from its relaxed length when a mass of 1.4 kg is hanging in equilibrium from the spring. (a) What is the spring constant? (b) How much elastic potential energy is stored in the spring? (c) A different mass is sus...

A motorist driving a 1200-kg car on level ground accelerates from 20.0 m/s to 30.0 m/s in a time of 5.0s. Neglecting friction and air resistance, determine the average mechanical power in watts the engine must supply during this time interval.

A top fuel drag racer with a mass of 500.0 kg completes a quarter-mile (402m) drag race in a time of 4.2s starting from rest. The car's final speed is 125m/s. What is the engine's average power output? Ignore friction and air resistance.

A spring with k=40.0 N/m is at the base of a frictionless 30.0 degree inclined plane. A 0.50-kg object is pressed against the spring, compressing it 0.20m from its equilibrium position. The object is then released. If the object is not attatched to the sp...