A 1500kg vehicle has its velocity reduced from 20m/s to 15m/s in 3.0 seconds. How large was the average retarding force?
Correct answer: C. -2500 N
- A. -500 N
- B. -1500 N
- C. -2500 N
- D. -3500 N
Explanation
To solve this problem, apply Newton's second law which relates force to mass and acceleration. The average retarding force can be calculated using the formula F = ma, where 'a' is the change in velocity over time. Here, the change in velocity is 20 m/s - 15 m/s = 5 m/s, over 3 seconds. Therefore, the average force is 1500 kg × (15 - 20) m/s / 3 s = -2500 N. The negative sign indicates the force is acting opposite to the direction of the vehicle's motion. Options -500 N, -1500 N, and -3500 N are incorrect because they result from incorrect application of the formula or arithmetic errors.
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