Question

plzzzzzz help????? ​

Answer 1

Correct Question:-

A boy of weight 50 N runs up a staircase of 45 steps in 9 s. The height of each step is 10 cm, so his power is

Answer:-

$\green{\bigstar}$ Power of the boy $\large\leadsto\boxed{\tt\purple{250 \: W}}$

• Given:-

Weight of the boy = 50 N

Number of steps in staircase = 45

Height of each step = 10 cm = 0.1 m

Time taken = 9 sec.

• To Find:-

Power of the boy.

• Solution:-

We know,

$\blue{\bigstar}$ $\large\underline{\boxed{\bf\red{P = \dfrac{W}{T}}}}$

where,

P = Power

W = Work done

T = Time taken

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Also,

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$\blue{\bigstar}$ $\large\underline{\boxed{\bf\red{W = mgh}}}$

where,

W = Work done

mg = weight of the body

h = Displacement

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Hence, the final formula:-

$\blue{\bigstar}$ $\large\underline{\boxed{\bf\red{P = \dfrac{mgh}{t}}}}$

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• Substituting in the Formula:-

➪ $\sf P = \dfrac{50 \times 10 \times 0.1 \times 45}{9}$

➪ $\sf P = \dfrac{500 \times 0.1 \times 45}{9}$

➪ $\sf P = \dfrac{50 \times 45}{9}$

➪ $\sf P = \dfrac{2250}{9}$

★ $\large\underline{\underline{\bf\pink{P = 250 \: W}}}$

Therefore, the Power of the boy will be 250 W.

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Answer 2

Step-by-step explanation:

5\times \frac{2}{5} = 25×

5

2

=2