Work Energy And Power Question 199
Question: A force of $ 2\hat{i}+3\hat{j}+4\hat{k}\ N $ acts on a body for 4 second, produces a displacement of $ (3\hat{i}+4\hat{j}+5\hat{k})m. $ The power used is [Pb. PET 2001; CBSE PMT 2001]
Options:
A) 9.5 W
B) 7.5 W
C) 6.5 W
D) 4.5 W
Show Answer
Answer:
Correct Answer: A
Solution:
$ P=\frac{\overrightarrow{F}.\overrightarrow{s}}{t}=\frac{(2\hat{i}+3\hat{j}+4\hat{k}).(3\hat{i}+4\hat{j}+5\hat{k})}{4} $
$ =\frac{38}{4}=9.5\ W $
