A box of mass 20 kg is sitting at the back of a Toyota Tundra which is travelling with a velocity of 35 mph. Find the coefficient of friction between the box and the truck so that the truck is able to stop within a distance of 20 m without the box sliding in the truck. (Use 1 mile = 1.609 km).
Find the kinetic energy of a sports car with a mass m = 2500 kg and travelling with a velocity v = 70 mph on the freeway (Use 1 mile = 1 .609 km).