Physics Answers

Sir Albert Einstein describes light as;

In a dentist's office an X-ray of a tooth is taken using X-rays that have a frequency of 6.30 x 10¹⁸ Hz. What is the wavelength in vacuum of these X-rays?

If the lever arm of a screw is 18 inches long and the pitch of the threads is 0.125 inch, how much weight will the jack lift if 50 pounds of force is applied at the end of the lever arm ignoring friction?

How much pull (F) would it take on the block and tackle rope to lift a 545 pounds engine?

How much force will it take to lift a 10 pounds weight with a wheel and axle if the axle is 2 inches in diameter and the wheel is 10 inches in diameter?

What is the maximum amount of weight that could be pulled up an inclined plane

if the force is limited to 50.75 pounds, the inclined plane is 12.25 feet long, and the

height is 54 inches?

a rigid tank holds 4 kg of water at 20 degree Celcius. If 200 kJ of heat is added to this system, what will be the final temperature? how much work is done in this process

A child slides across a floor in a pair of rubber-soled shoes. The friction force acting on each foot is 20.0 N. The footprint area of each shoe sole is 14.0 cm2, and the thickness of each sole is 5.00 mm. Find the horizontal distance by which the upper and lower surfaces of each sole are offset. The shear modulus of the rubber is 3.00 MN/m2.

A 24-N horizontal force is applied to a 40-N block initially at rest on a rough horizontal surface. If the coefficients of friction are µs = 0 .5 and µk = 0 .4, find the magnitude of the frictional force on the block.

The deepest point in the ocean is in the Mariana Trench, about 11 km deep, in the Pacific. The pressure at this depth is huge, about 1.13 x 10^8 Pa. (a) Calculate the change in volume of 1.00 m3 of seawater carried from the surface to this deepest point. (b) The density of seawater at the surface is 1.03 x 10^3 kg/m3. Find its density at the bottom. (c) Explain whether or when it is a good approximation to think of water as incompressible.