A man pushes a box across a floor. As he increases the force he applies horizontally to the box A) the kinetic friction decreases
B) the kinetic friction may increase or decrease depending on the velocity of the box
C) the kinetic friction remains the same
D) the kinetic friction increases

Atank has a shape of a cone with a radius at the top of 2 m and a height of 5 m. the tank also has a 1 m spout at the top of the tank. the tank is filled with water up to a height of 2 m. find the work needed to pump all the water out the top of the spout. (use 9.8 m/s2 for g and the fact that the density of water is 1000 kg/m3.)