What is the power of a child that has done work of 50J in 10seconds.
(a)50W (b)20W (c)30W (d)5W
Answers
Given:
We have,
- Work done = 50 J
- Time taken = 10 s
To be calculated:
Calculate the power of a child?
Formula used:
Power = Work done / Time taken
Solution:
We know that,
Power = Work done / Time taken
★ Substituting the values in the above formula,we get
Power = 50 J / 10 s
= 5 J/s
= 5 W [ 1 J/s = 1 W ]
Thus, the power of a child is 5 Watts.
Knowledge Enhancer:
Power: Rate of work done is called power.
- S.I unit is Watt
- Power is scalar quantity [ It has only magnitudes ]
- 1 Watt = 1 J / 1 S
Others units :
- Kilowatt ( Kw )
- Megawatt ( mw )
- Horse power ( h.p )
✰Question ✰
▪ What is the power of a child that has done work of 50J in 10seconds.(a)50W (b)20W (c)30W (d)5W
✰Given:-
➧ Work done =50 Joule (J)
➧Time taken ( t) = 10s
✰To Find :-
➧Power (p) of the a child???
✰ Solution ✰
▪ By using this formula
➠ Power =work done /time taken
➠ P= w/t
➠P = 50/10
➠P = 5 watt.
∴The power of the child is 5 watt.
hence, option (d) 5w is the correct answer
✰Extra Knowledge ✰
➧ Power is defined as the rate of doing work.
OR
The rate at which energy is transferred by an object is called power.
➧ SI unit of Power is watt.
➧ 1 horse power (hp) = 746watt.
➧ 1 kwh =3.6 × 10^6 J
➧ 1 watt is defined as the if work is done at the rate of 1 Joule per second.
➧ 1 watt =1 Joule /second