According to newton's second law of motion how much force will be required to accelerate an object at the same rate if it's mass is reduced by half?
a - four times the amount of force is needed
b - half the amount of force will be required
c- no change
d - twice the amount of force will be required

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.)