Question
A person jumps from a height on soft sand. Which one of the following is the correct reason for less likely injury to the person?
NDA
General Ability
General Science
2026
NDA 2026 (Phase 1)
NDA General Ability Question (2026) — Solution
Options
- A. The sand exerts no reaction force.
- B. The sand reduces the change in momentum.
- C. The sand increases the impact time.
- D. The sand increases the momentum.
Answer
C. The sand increases the impact time.
Step-by-step solution
According to Newton's second law of motion, the average force exerted on a body is equal to the rate of change of momentum, F = p t . When a person jumps from a height onto soft sand, the sand yields under the person's weight. This increases the time of impact t for the person to come to rest. Since the change in momentum p remains the same (as the initial velocity just before impact and the final velocity of zero are unchanged), an increase in the impact time t results in a significant decrease in the average force F exerted on the person. A smaller force reduces the likelihood of injury. Therefore, the soft sand increases the impact time.
Related: General Ability — General Science · All PYQ Banks