3)110 Watts of power was used to move a 50 kg rock 50 m in 30 s. How much work was needed and how much force was used to accomplish this? The rock then fell 75 m off a cliff, what wasits
gravitational potential energy of the rock at the top of the cliff? What was its speed just before therock
hit the ground at the bottom of the cliff?

Suppose a force of 60 n is required to stretch and hold a spring 0.1 m from its equilibrium position. a. assuming the spring obeys hooke's law, find the spring constant k. b. how much work is required to compress the spring 0.5 m from its equilibrium position? c. how much work is required to stretch the spring 0.6 m from its equilibrium position? d. how much additional work is required to stretch the spring 0.1 m if it has already been stretched 0.1 m from its equilibrium? a. kequals 600