MCQ
A bicyclist comes to a skidding stop in $10m.$ During this process, the force on the bicycle due to the road is $200N$ and is directly opposed to the motion. The work done by the cycle on the road is:
- A$+2000J$
- B$-200J$
- ✓zero
- D$-20,000J$
✓
Answer
Correct option: C.
zero
As the friction is present in fhis problem,
so mechanical energy is not conserved.
So energy will be lost due to dissipation by friction
Here, work is done by the frictional force on the cycle and is equal to $200 \times 10 = -2000J$
As the road does not move at all, therefore, work done by the cycle on the road is zero.
Important point.
We should be aware that here the energy of bicyclist is lost during the motion, but it is lost due to friction in the form of heat.
so mechanical energy is not conserved.
So energy will be lost due to dissipation by friction
Here, work is done by the frictional force on the cycle and is equal to $200 \times 10 = -2000J$
As the road does not move at all, therefore, work done by the cycle on the road is zero.
Important point.
We should be aware that here the energy of bicyclist is lost during the motion, but it is lost due to friction in the form of heat.
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