A man grows into a giant such that his linear dimensions increase by a factor of 9. Assuming that his density remains same, the stress in the leg will change by a factor of:
- (A)81
- (B)
- (C)9✓ Correct
- (D)
Answer: (C)
Solution
Stress in the legs is weight divided by cross-sectional area. Scale every length by : the mass, and hence the weight, grows as the volume, a factor , while the leg's cross-section grows as an area, a factor . The stress therefore scales as , increasing ninefold.
JEE Main · 2017 · 02 Apr 2017 · Offline · Single correct option