Question

A boy of mass 40 kg runs up a staircase of 45 steps in 9 sec. If the height of each step is 15cm. Then its power is (g = 10 m/s) ​

Answer 1

Given,

• Mass(m) = 40 kg
• Height(h) = 40 × 15 = 600 cm = 6 m
• Time(t) = 9 s
• Acceleration Due to gravity(g) = 10 m/s

As we know,

$\boxed{\bold{\bf{Potential \ Energy \ (PE) \ = m \times g \times h}}}$

Applying the values to the equation,

$\sf{\implies PE=40\times 10\times 6}$

$\sf{\implies PE=2400\ J}$

As we know,

$\boxed{\bold{\bf{Power(P)=\frac{PE}{t}}}}$

Applying the values to the equation,

$\sf{\implies P = \frac{2400}{9}}$

$\sf{\implies P = 266.67 \ W }$

$\huge{\boxed{\bold{\sf{\therefore Power(P)=266.67 \ W}}}}$