Question

boy does 400 J of work in lifting a suitcase to the first floor in 30 s. How much power

does he spent​

Answer 1

Given:-

• Work done W = 400J

• Time taken t = 30s

To Find:-

• Power spent by lift P.

Solution:-

As we know that Power is defined as the rate of doing work at per unit time .

SI unit of Power is Watt.

→ Power = Workdone/Time

→ P = W/t

Substitute the value we get

→ P = 400/30

→ P = 40/3

→ P = 13.33 Watt

∴ The power spent by the boy in lifting the suitcase is 13.33 Watt.

Answer 2

$</p><p></p><p></p><p> \sf \implies \huge{ \boxed{ \bold{\underline{Given : }}}} \\ \\ \\ \sf \bullet \large \: </p><p></p><p>Boy \: does \: the \: work \: = 400 \: Joule \\ \\ </p><p></p><p> \sf \bullet \large \: Time \: taken \: = 30 \: second \\ \\ \\ </p><p></p><p></p><p>\sf \implies \huge{ \boxed{ \bold{To Find : }}} \\ \\ </p><p></p><p> \sf \large \iff \: Power \\ \\ \\ </p><p></p><p>\sf \implies \huge{ \boxed{ \bold{Solution}}} \\ \\ \\ </p><p></p><p></p><p> \sf \large \iff \: { \boxed{ \bold{Power = \frac{work \: done}{time} }}} \\ \\ \sf \implies \large \: power \: = \cancel\frac{400}{30} \: j \: {s}^{ - 1} \\ \\ \sf \implies \large \: power \: = \cancel \frac{40}{3} \\ \\ \sf \implies \large \: power \: = 13.33 \: j {s}^{ - 1} \\ \\ \\ \\ \therefore \sf \large \:{ \red{ \boxed{ \underline{ \underline{ \bold{ power \: = 13.33 \: j {s}^{ - 1} }}}}}}$