Question

A boy of mass 50 kg runs up a staircase of 45 steps in 9 s. If the height of each step is 15 cm, find his power. Take g = 10 m s 2​

Answer 1

Answer:

375

Explanation:

Given mass of body (m)=50kg

h=45×15=675cm=6.75m

t=9s δ=10m

Potential energy =mgh

=(50×10×6.75)

=3375

Power of the body= Time/Potentialenergy

= 9/3375

=375W

Answer 2

ProvidEd that:

• Mass of boy = 50 kg
• Staircase steps = 45 steps
• Time = 9 seconds
• Height of each step = 15 cm
• g = 10 m/s sq.

To calculaTe:

• Power of the boy

SoluTion:

• Power of the boy = 375 Watts

UsiNg concepts:

• Formula to convert cm into m
• Power formula

UsiNg formulas:

• ${\small{\underline{\boxed{\pmb{\sf{1 \: cm \: = \dfrac{1}{100} \: m}}}}}}$

• ${\small{\underline{\boxed{\pmb{\sf{Power \: = \dfrac{mgh}{t}}}}}}}$

Where, m denotes mass, g denotes acceleration due to gravity, h denotes height and t denotes time taken!

RequirEd solution:

~ Firstly let us convert cm into m!

$:\implies \sf 1 \: cm \: = \dfrac{1}{100} \: m \\ \\ :\implies \sf 15 \: cm \: = \dfrac{15}{100} \: m \\ \\ :\implies \sf 15 \: cm \: = 0.15 \: metres \\ \\ {\pmb{\sf{Henceforth, \: converted!!!}}}$

~ Now let's calculate the height of the stairs!

Explanation: We have to multiply height of each steps of the stairs by total steps!

$:\implies \sf 0.15 \times 45 \\ \\ :\implies \sf Height \: = 6.75 \: metres \\ \\ {\pmb{\sf{Henceforth, \: finded!!!}}}$

~ Now let's calculate the power by using suitable formula!

$:\implies \sf Power \: = \dfrac{mgh}{t} \\ \\ :\implies \sf Power \: = \dfrac{50 \times 10 \times 6.75}{9} \\ \\ :\implies \sf Power \: = \dfrac{500 \times 6.75}{9} \\ \\ :\implies \sf Power \: = \dfrac{500 \times 6.75}{9} \\ \\ :\implies \sf Power \: = \dfrac{3375}{9} \\ \\ :\implies \sf Power \: = 375 \: Watts$

Henceforth, his power = 375 W