A boy exerts a force of 225 n on a lever to raise a 1250 n rock a distance of 0.13 m. if the lever is frictionless, how far did the boy have to move his end of the lever?

A hot air balloon is filled with 1.37 * 106 l of an ideal gas on a cool morning (11 °c. the air is heated to 117 °c. what is the volume of the air in the balloon after it is heated? assume that none of the gas escapes from the balloon.

Energy is transferred in solids by conduction, which means that? A: Heat travels in both directions B: Heat travels from the cooler object to the hotter object C:Heat travels from the hotter object to the cooler object D: Heat does not travel

If you increased the momentum of an object without increasing it inertia then what do you have

A wave has a wavelength of 6 mm and a frequency of 9 hertz. What is its speed? what is the answer and units?

Conventional current- a. is the direction an electron would move in an electric field. b. is from + to - c. is from - to + d. both a and c

Which equation best expresses the first law of thermodynamics, assuming Q is heat, U is internal energy, and W is work? A.ΔW = ΔQ + ΔU B.ΔW = ΔU - ΔQ C.ΔQ = ΔU+W D.ΔU=Q - W

Why are the action and reaction forces described by Newton's third law of motion excluded in the free-body diagram of an object?

The small depression inside the bend of the elbow is the

If r = KL/d2 find L to the nearest tenth foot if r = 2.5 ohms, k = 10.8 and = 85 mil

A 1500 kg car accelerates uniformly from rest to reach 10.0 m sin 5.00 s. Determine (i) the average power delivered by the engine.