A boy of 50 kg mass climbs 44 stairs in 10 seconds. If the height of each stair is 15cm then find his power?
A. 337.5ms
B. 387.5W
C. 330J
D. 330W
Answer: Option D
This Question Belongs to Physics GK Chapter Wise >> Work, Energy And Power
Join The Discussion
Comments (2)
Related Questions on Work, Energy and Power
Which of the following can do more work?
A. A raised hammer
B. A bullet fired by the gun
C. A moving stone
D. A rotating wheel
A. Energy released by a moving object
B. Energy emitted during mechanical work
C. The sum of the kinetic energy and potential energy of an object
D. Equal to the rate of work done
A. Chemical energy
B. Potential energy
C. Kinetic energy
D. Heat energy
The correct answer is *B. 330 W* (the closest option is *D. 330W*).
*Solution:*
1. *Total height climbed*:
$$h = 44 imes 0.15 ext{m} = 6.6 ext{m}$$
2. *Work done (potential energy gained)*:
$$W = mgh = 50 ext{kg} imes 10 ext{m/s}^2 imes 6.6 ext{m} = 3300 ext{J}$$
3. *Power*:
$$P = rac{W}{t} = rac{3300 ext{J}}{10 ext{s}} = 330 ext{W}$$
So the boy's power is *330 W*. 🚀
The correct answer is *B. 330 W* (the closest option is *D. 330W*).
*Solution:*
1. *Total height climbed*:
$$h = 44 imes 0.15 ext{m} = 6.6 ext{m}$$
2. *Work done (potential energy gained)*:
$$W = mgh = 50 ext{kg} imes 10 ext{m/s}^2 imes 6.6 ext{m} = 3300 ext{J}$$
3. *Power*:
$$P = rac{W}{t} = rac{3300 ext{J}}{10 ext{s}} = 330 ext{W}$$
So the boy's power is *330 W*. 🚀