You're trying to stop a car that is rolling down-hill. Gravity is pulling it forward with a force of 200 N. If the car has a mass of 650 kg, and you want to it accelerate at -0.15 m/s/s, what force do you need to apply to the car? (Your goal is to find the actual number for the force that you are applying.)

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.