A student applies a force to a cart to pull it across the gym at a constant speed during a physics lab. A force of 20.8 N is applied to pull a 3.00-kg loaded cart 8 meters. Determine the work done upon the cart.

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?