A frictionless toy car is placed on a ramp, which is inclined at an unknown angle with respect to the horizontal. Starting from rest, the car is allowed to roll freely down the ramp. After a time interval of Δ=0.67 s, the car has traveled a distance of =1.2 m down the ramp and is moving with speed f. Find the speed of the car at the end of the 0.67 s time interval.

Suppose that a cylindrical tank 6 meters high with a radius of 2 meters is filled to the rim with water. the tank is buried so that the top of the tank is 1 meter below ground level. the space above the tank is not filled with water. calculate how much work needs to be done by a pump to pump the water out of the tank up to ground level. (the water weighs 9,800 newtons per cubic meter.)