Question

4. A pump is used to lift 300 kg of water from a depth of 50 m in 10 s. Calculate
a. the work done by the pump.
b. the power at which the pump works.
[Ans. a. W = 147000 J b. P = 14700 W ]

plzzzz clear answer do not faltu comments ​

Answer 1

(a) Work done :-

As we know that ,

• Work = mgh

→ Work = 300 × 10 × 50

→ Work = 150000 J or 150 kJ

Hence , work done = 15 × 10⁴ J

(b) Power :-

As we know that ,

• Power = Work/time

Simplifying ,

• Power = mgh/t

From the above solution , already we got , work = 150000 J . So ,

=> Power = 150000/10

=> Power = 15000 W or 15 kW

Hence , power = 15kW

Answer 2

${\large{\bold{\sf{\underline{Understanding \; the \; question}}}}}$

➦ This question says that there is a pump and it is used to lift 300 kg of water from a depth of 50 m in 10 seconds. We have to calculate the following terms –

a. The work done by the pump.

b. The power at which the pump works.

${\large{\bold{\sf{\underline{Given \; that}}}}}$

➦ A pump is used to lift 300 kg of water

➦ It lift water from depth of 50 metres

➦ And it lift water in 10 seconds

${\large{\bold{\sf{\underline{To \; find}}}}}$

➦ The work done by the pump.

➦ The power at which the pump works.

${\large{\bold{\sf{\underline{Solution}}}}}$

➦ The work done by the pump = 150000 Joules or 15 × 10⁴ Joules.

➦ The power at which the pump works = 15000 Watts

${\large{\bold{\sf{\underline{Using \: concepts}}}}}$

➦ Formula to find work done

➦ Formula to find power

${\large{\bold{\sf{\underline{Using \: formulas}}}}}$

➦ Work done => mgh

➦ Formula to find power => Work / Time

${\large{\bold{\sf{\underline{Where,}}}}}$

➦ m denotes mass

➦ g denotes acceleration due to gravity

➦ h denotes height

${\large{\bold{\sf{\underline{Full \: solution}}}}}$

~ Finding work done

➦ Work done = mgh

➦ Work done = 300 × 10 × 50

➦ Work done = 3000 × 50

➦ Work done = 150000 J or 150 KJ too

• Therefore, work doned = 15 × 10⁴ Joules or 150000 Joules

~ Finding power

➦ Power = Work / Time

➦ Power = 150000 / 10

➦Power = 15000 Watts or 15 KW too

• Henceforth, power = 15000 Watts or 15 KW