A car moving with a speed of 50km/h can be stopped by brakes after at least 6m. If the same car is moving at a speed of 100km/h the minimum stopping distance is:
Correct answer: D. 24 m
- A. 6 m
- B. 12 m
- C. 18 m
- D. 24 m
Explanation
Option D is correct.Given data: velocity 1=v1 =50km/h velocity 2 = v2= 100km/hdisplacement 1=d1 =6m find out: d2=? Solution :according to the work energy principle d=-mvi/2fFor the same car d is directly proportional to vid2/d1 =v22 / v12 d2 =v22 / v12 * d1 =1002/502 * 6 = 24m
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About Work and Energy
Work transfers energy when a force causes displacement, while kinetic energy, gravitational potential energy and power describe motion, position and the rate of energy transfer. The work-energy theorem links net work with change in kinetic energy, and efficiency accounts for energy losses rather than treating them as energy destruction.
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