1) A mass of 3.0 kg is subject to a force F(x) = 8.0 N — (4.0 N/m)x The potential energy of the mass is zero at x = 0. What is the potential energy of the mass at x = 2.0 in?
A) 4.0 J

B) 0.0 J

C) 8.0 J

D) -4.0 J

E) -8.0 J

2) At what rate is a 60.0kg boy using energy when he runs up a flight of stairs 10.0m high. in B.000
A) 80.0 W

B) 75.0 W

C) 736 W

D) 4.80 kW

E) 48 W