A person 'A' pushes a body of 5 kg placed on a rough surface of co-efficient of friction 0.3 by a distance of 4 m in 15 seconds. Another person 'B' pushes the body of 7 kg on same surface by a distance of 3 m in the same time. Who has more energy and power?a)Ab)Bc)Both A and B have developed equal power but B has more energyd)Both A and B have developed equal power but A has more energyCorrect answer is option 'B'. Can you explain this answer?

Question

Answer

Answer

F'A=15N,W'A=15×4=60J,P'A=60/15=4wattF'B=21N,W'B=21×3=63J,P'B=63/15=4.2wattSo the answer will be option B

Answer

Hii Kush..... yess u can do this P=W done/time , Work done = F×s and so on and u will see the result

Answer

For person A,
Mass of body, m₁= 5kg
Coefficient of friction, μ =0.3
So, The force of friction,
F1= μm₁g=0.3 X 5 X 10=15N
Displacement, S₁=4m
Therefore,
Work done, W₁=15X4=60J
Time taken, t₁=15sec
So, Power, P₁=60/15=4W
For Person B
Mass of body, m₂=7kg
Coefficient of friction, μ =0.3
So, The force of friction,
F₁= μm₂g=0.3 X 7 X 10=21N
Displacement, S2=3m
Therefore,
Work done, W₂=21X3=63J
Time taken, t₂=15sec
So, Power, P₃=63/15=4.2W

So person B has more energy and power.

Answer

Analysis:
- Person A pushed a 5 kg body over a distance of 4 m in 15 seconds.
- Person B pushed a 7 kg body over a distance of 3 m in the same time.

Calculations:
- Work done by person A = Force x Distance = 5 kg x 9.8 m/s^2 x 4 m = 196 J
- Work done by person B = 7 kg x 9.8 m/s^2 x 3 m = 205.8 J

Energy:
- Person B has more energy as they did more work on the body compared to Person A.

Power:
- Power is the rate of doing work, calculated as Work done / Time taken.
- Power developed by person A = 196 J / 15 s = 13.07 W
- Power developed by person B = 205.8 J / 15 s = 13.72 W

Conclusion:
- Person B has more energy as they did more work on the body.
- Person B also has more power as they developed a higher rate of doing work compared to Person A.

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