A ride at an amusement park attaches people to a bungee cord, pulls them straight down to the ground, and then releases them into the air. When they
are pulled to the ground, the bungee cord (which has a stiffness constant of
35 N/m) is stretched 100 m beyond its unloaded length. What restraining
force is required to hold a man with a mass of 90 kg to the ground just before
he is released? (Recall that g = 9.8 m/s2)

Which feature of a heating curve indicates a change ofn state

A250-n box is at rest on a frictionless horizotal floor. then a person shoves the box with a non-zero force of magnitude p. which statement best describes the relationship betweeen p and the motion of the box after it was shoved? -the box will not move when p< 250n but otherwise will accelerate at a constant rate that is directly proportional to p - the box will begin moving at a speed that is directly proportional to p, then will gradually slow to a halt -the box will move with constant velocity at a speed that is directly proportional to p -box will accelerate across the floor at a constant rate that is directly proportional to p

An insulated 40 ft^3 rigid tank contains air at 50 psia and 120°f. a valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. the air temperature during this process is kept constant by an electric resistance heater placed in the tank. determine the electrical work done during this process.