JEE Mains · Physics · STD 11 - 5. work,energy,power and collision
To maintain a speed of \(80\,km / h\) by a bus of mass \(500\,kg\) on a plane rough road for \(4\,km\) distance, the work done by the engine of the bus will be \(........\,kJ\). [The coefficient of friction between tyre of bus and road is \(0.04]\).
- A \(785\)
- B \(786\)
- C \(777\)
- D \(784\)
Answer & Solution
Correct Answer
(D) \(784\)
Step-by-step Solution
Detailed explanation
For constant speed, WD by engine + WD by friction \(=0 \quad\) [by WET \(]\) \(WD _{\text {engine }}=- WD _{\text {friction }}=-[-\mu mgx ]\) \(=0.04 \times 500 \times 9.8 \times 4 \times 10^3\) \(=784\,kJ\)
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