Question

the power of boy weighting 50 kg who climb of 8m high in 4 second is​

Answer 1

Given:-

• Mass of boy (m) = 50kg

• Height climb by him (h) = 8m

• Time taken (t) = 4s.

To Find:-

• Power of boy (p).

Solution:-

As we know that ,the acceleration due to gravity is 9.8m/s².

⟹ Work done = Mass×acceleration × height

⟹ W = mgh

Put the value,we get

⟹ W = 50×9.8×8

⟹W = 490×8

⟹ W = 3920 Joule .

∴ The Work done by the boy is 3920J.

The rate of doing work is called Power

⟹ Power = Workdone/Time

⟹ p = W/t

Put the value ,we get

⟹ p = 3920/4

⟹ p = 980Watt

∴The power of boy is 980 Watt.

Additional Information !!

✧ The rate of doing work is called power .

OR

The rate at which energy is transferred by an object is called the Power delivered by that object.

✧ SI unit of Power is Watt (W).

✧ Mathematical Term

⟹ p = W/t

✧ 1 horse Power = 746 Watt .

✧ The work done by a force acting on an object is equal to the product of force and the displacement of the object in the direction of the force.

✧ SI unit is Joule (J).

Answer 2

AnswEr:

☯ Given:-

$\qquad\bullet\normalsize\sf\ Weight \: of \: boy(w) \: = \: 50kg$

$\qquad\bullet\normalsize\sf\ Height \: climb \: by \: boy(h) \: = \: 8m$

$\qquad\bullet\normalsize\sf\ Time \: taken \: by \: boy(t) \: = \: 4s$

☯ To Find:-

$\qquad\bullet\normalsize\sf\ Power \: of \: boy(P)$

☯ Solution:-

$\underline{\bigstar\:\sf{According \: to \: given \: in \: question:}}$

As we know, that the work done in a lifting body is the product of mass, acceleration and vertical distance or height;

$\twoheadrightarrow\sf\ W = m \times\ g \times\ h$

$\twoheadrightarrow\sf\ W = 50 \times\ \: \underbrace{9.8 \times\ 8}_{multiply \: both}$

$\twoheadrightarrow\sf\ W = 50 \times\ 78.4$

$\twoheadrightarrow\sf\ W =3920 \: joule$

Again; we know that Power is the fraction of total work done upon total time taken;

$\twoheadrightarrow\sf\ Power(P) = \frac{Work \: done \: \left(w \right)}{Time \: taken \: \left(t \right)}$

$\twoheadrightarrow\sf\ Power(P) = \frac{3920}{4}$

$\twoheadrightarrow\sf\ Power(P) = \frac{\cancel{3920}}{\cancel{4}}$

$\twoheadrightarrow\sf\ Power(P) = 980 \: watt$

$\therefore\:\underline{\textsf{The\: power \: of \: boy \: is}{\textbf{\: 980watt}}}$

______________

$\underline{\bigstar\:\sf{Additional \: Information :}}$

⋆ Work :-

• Work is done when a force produces motion.
• Work done in a moving body is equal to the product of force & displacement.
• When work is done against gravity then the amount of work done is equal to the product of weight of the body and the vertical distance through which the body is lifted.
• The SI unit of work is Joule.

⋆ Power:-

• Power is the work done per unit time.
• In other words, power is the fraction of total energy consumed upon Time taken.
• The SI unit of power is watt.