Question

A boy has to do 450 J of work in 30 seconds to lift luggage to the roof of a bus. How much power does he spend? *

Answer 1

Given:-

• Work done by Boy (w) = 450J

• Time taken (t) = 30s

To Find:-

• Power spend by by him (P).

Solution:

By using this formula

⟹ Power = work done/Time

⟹P = w/t

put the value which is given above

⟹ P = 450/30

⟹P = 15 watt.

∴ He spend 15 Watt Power.

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

Aɴsᴡᴇʀ :

➥ The power spend by boy = 15 watts

Gɪᴠᴇɴ :

➤ Work done by boy (w) = 450 J

➤ Time take by boy (t) = 30 sec

Tᴏ Fɪɴᴅ :

➤ Power spend by boy = ?

Sᴏʟᴜᴛɪᴏɴ :

$\sf{: \implies Power = \dfrac{Work}{Time} }$

$\sf{: \implies Power = \cancel{\dfrac {450}{30}}}$

$: \implies \green{\underline{ \overline{ \boxed{ \purple{ \bf{ \: \: Power = 15 \: watts\: \: }}}}}}$

Hence, the power spend by boy is 15 watts.

⠀⠀ ⠀⠀

▭▬▭▬▭▬▭▬▭▬▭▬▭▬▭▬▭▬

Another equation of power

⪼ $\sf{Power = \dfrac{Work}{Time}}$

⪼ Power = Force × Velocity

⪼ $\sf{Power = \dfrac{Force \times Displacement}{Time}}$

▭▬▭▬▭▬▭▬▭▬▭▬▭▬▭▬▭▬