Question

17 How large an average force is required to stop a 1400-kg car in 5.0 s if the car’s initial speed is 25 m/s?
2000 N
3500 N
9000 N
7 000N

18 Which of these is NOT a statement of Newton’s law of universal gravitation?
gravitational force between two particles is attractive as well as repulsive
gravitational force acts along the line joining the two particles
gravitational force is directly proportional to the product of the masses of the particles
gravitational force is inversely proportional to the square of the distance of the particles apart