3water within a piston–cylinder assembly, initially at 10 lbf/in.2 , 500°f, undergoes an internally reversible process to 80 lbf/in.2 , 800°f, during which the temperature varies linearly with specific entropy. for the water, determine the work and heat transfer, each in btu/lb. neglect kinetic and potential energy effects.

What is the coefficient of kinetic friction μk between the block and the tabletop?

The illuminance of a surface varies inversely with the square of its distance from the light source. if the illuminance of a surface is 120 lumens per square meter when its distance from a certain light source is 6 meters, by how many meters should the distance of the surface from the source be increased to reduce its illuminance to 30 lumens per square meter?

Relative to the ground below, how many joules of potential energy does a 1000-kg boulder have at the top of a 5-m ledge?