3 A ball rolls at a speed of 4 km/h towards the back of a bus traveling forward at a speed of 35

km/h. What is the magnitude of the ball's velocity relative to the ground?

(33 Points)

O A: 30 km/h

B: 31 km/h

O c: 35 km/h

OD: 39 km/h

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