A 400 Kg truck rushing through the street at 20 m/s crashes into a 50 Kg car making a turn at 2 m/s. The car is bounces off the bottom of truck at 142 m/s, what is the final velocity of the truck?

Two pans of a balance are 24.1 cm apart. the fulcrum of the balance has been shifted 1.33 cm away from the center by a dishonest shopkeeper. by what percentage is the true weight of the goods being marked up by the shopkeeper? assume the balance has negligible mass. answer in units of %.