Question 7
Work, Energy and PowerA 50.0 kg block is dropped on a spring from a point 10 m above (Fig. 2). If the force constant of the spring is 4.0 × 104 N m−1, find the maximum compression of the spring. [g = 10 m s−2]
- A.1.25 m
- B.0.50 m
- C.0.25 m
- D.0.05 m
Show the answer and explanation
Answer: B (0.50 m)
Explanation
The block's potential energy is stored in the spring: mgh = ½ke². 50 × 10 × 10 = ½ × 4 × 104 × e², so e² = 0.25 and e = 0.5 m.