A set of pulleys is used to raise a 200 N crate 5 m. to fo this the operator applies a force of 50 N and pulls in 25 m of rope. Find the efficiency of the pulley system.

A: 50%

B: 62.5%

C: 75%

D: 80%

In a swimming race, miho swam the first 50m in42s. she swam the second 50m in40s. what was miho's average speed during the race?

What is scientific reasoning?

N capacitors are connected in parallel to form a "capacitor circuit". The capacitance of first capacitor is C, second one is C/2 and third one is C/4, forth one is C/8 and so on. Namely, capacitance of a capacitor is one-half of the previous one.

Use the slit example to explain why you can hear a noise in another room through an open door.

If all the atoms in a molecule of a substance are alike then the substances is

Which statements accurately describe the Doppler effect?

Describe how mass and distance affect gravitational force.

a bike can climb the inclined road at uniform speed of 72 km/hr by applying force 500N what will be the power applied by the bike?

A wave has a wave length of 2 m and a frequency of 500 Hz, what is its speed?

Can anything block a magnet's force feild?