Question

A particle of mass 3 kg moves under the force of $4\hat{i}+8\hat{j}+10\hat{k}$ N. If the particle starts from rest and was at origin initially. Its new co-ordinates after 3 seconds is :

• A. $(4,8,10)$
• B. $(6,12,15)$
• C. $(2,4,5)$
• D. $(3,6,7.5)$

Answer 1

The correct option is B $(6,12,15)$

$\overrightarrow{F}=4i+8j+10k\overrightarrow{a}=\frac{4}{3}\hat{i}+\frac{8}{3}j\widehat{+}\frac{10}{3}\hat{k}$

$\overrightarrow{s}=0+0.5a{t}^2;t=3;=4.5a$

$\overrightarrow{s}=\frac{4}{3}\times 4.5\hat{i}+\frac{8}{3}\times 4.5\hat{j}+\frac{10}{3}\times 4.5\hat{k}=6\hat{i}+12\hat{j}+15\hat{k}$