Answer:
Willie pushed on the cart with 1500 newtons of force.
James pulled on a rope attached to the cart with 550 newtons of force.
Biff pushed on the cart with 600 newtons.
To calculate the net force, we need to take into account the direction of these forces. If all the forces are applied in the same direction, we can simply add them up:
Net Force = 1500 N (Willie) + 550 N (James) + 600 N (Biff) = 2650 newtons
So, the net force acting on the cart is 2650 newtons, assuming all the forces are acting in the same direction.