Question

A 60 kg person climbs stairs of total height of 20 m in two minutes, calculate
the power delivered. (g = 10 ms-2]​

Answer 1

weight = 60 × 10 = 600N

time = 2min = 120sec

Work done = 600 × 20 = 12000J

Power = 12000/120 = 1200Watts

Answer 2

$\sf{Solution}$

Step by step explanation:-

Given:-

• Mass = 60kg
• Height = 20m
• Time = 2 minutes
• g = 10m/s²

To find :-

Power ?

Concept:-

We know that power = $\sf\dfrac{workdone}{time}$

As we know that Work done may be potential energy or kinetic energy or electrical energy ,elastic energy etc

Here according to question Work done should be

W = change in potential energy = mgh

So,

By the above concept this is the formula

Power = $\sf\dfrac{mgh}{t}$

Solution:-

Substuite in formule

p = $\sf\dfrac{mgh}{t}$

T = 2min

1 min = 60seconds

2min = 2 ×60= 120 seconds

p = $\sf\dfrac{(60)(10)(20)}{120}$

p = $\sf\dfrac{12000}{120}$

p = $\sf\dfrac{(120) (100)}{120}$

power = 100watts

Power units are watts

So, power = 100watts