a boy of mass 40 kg runs up flight of 50 steps each 10cm high in 5 second. find 1) the work done by the body 2) the power developed (g=9.8m*-2
Answers
Required Answer:
Given:
- Mass of the boy (m) = 40 kg
- Time taken (t) = 5 s
Also, here it is given that he runs up flight of 50 steps each 10 cm high. That is,
- Height (h) = 50 × 10 cm
→ Height (h) = 500 cm = 5m
To calculate:
- Work done (W)
- Power developed (P)
Calculation:
• Calculating work done:
As we know that,
→ Work done is equal to the product of weight (mass times gravity) of the body and the height , when work is done against gravity. SI unit of work done is Joule (J). Work is a scalar quantity.
Formula:
- W = mgh
Where,
• W = work done
• m = mass of the object
• g = acceleration due to gravity
• h = height attained
Insert the values in the above formula-
→ W = 40 × 9.8 × 5
→ W = 200 × 9.8
→ W = 1960 Joule
Thus, work done is 1960 J.
• Calculating power developed:
As we know that,
→ Power is defined as work done per unit time.Power is a scalar quantity. SI unit of power is watt (W).
Formula:
- P = W/t
Where,
• P = Power
• W = Work done
• t = time
Insert the values in the above formula-
→ P = 1960/5
→ P = 392 W
Thus, power developed is 392 W.
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