Vectors Question 167
Question: A force vector applied on a mass is represented as $ \vec{F}=6\hat{i}-8\hat{j}+10\hat{k} $ and accelerates with $ 1\ m/s^{2} $ . What will be the mass of the body in kg.
[CMEET 1995]
Options:
A) ? 2
B) 8
C) ? 7
D) ? 8
Correct Answer: D For perpendicular vector $ \overrightarrow{A}.\overrightarrow{B}=0 $ Therefore $ (5\hat{i}+7\hat{j}-3\hat{k}).(2\hat{i}+2\hat{j}-a\hat{k})=0 $ Therefore $ 10+14+3a=0 $Show Answer
Answer:
Solution:
$ \Rightarrow $ $ a=-8 $