Laws of Motion - Result Question 5
5. A body under the action of a force
$\vec{F}=6 \hat{i}-8 \hat{j}+10 \hat{k}$, acquires an acceleration of $1 m / s^{2}$. The mass of this body must be [2009]
(a) $10 kg$
(b) $20 kg$
(c) $10 \sqrt{2} kg$
(d) $2 \sqrt{10} kg$
Show Answer
Answer:
Correct Answer: 5. (c)
Solution:
- (c) $\vec{F}=6 \hat{i}-8 \hat{j}+10 \hat{k}$,
$|\overrightarrow{{}F}|=\sqrt{36+64+100}=10 \sqrt{2} N$
$(\because F=\sqrt{F_x^{2}+F_y^{2}+F_z^{2}})$
Given, $a=1 ms^{-2}$
$\because F=ma \Rightarrow m=\frac{10 \sqrt{2}}{1}=10 \sqrt{2} kg$
