What is the period of a 4.12 m long pendulum?

The specific heat of silver is 0.057 calories/gram°c. if 10.0 grams of silver were heated and the temperature of the sample changed by 20.0°c, how many calories of heat energy were absorbed by the sample?

The speed of light in a material is 0.50 c. what is the critical angle of a light ray at the interface between the material and a vacuum?

Using a wheel and axle, a farmer is trying to lift a bucket of water from the bottom of a well. the larger wheel has a radius of 40 cm compared to the axle that has a radius of 10 cm. if a bucket of water is 50 n, then how much effort is required to raise it? 12.5 n 200 n 2 n 500 n