Question

The position $x$ of a particle moving along $x-$axis at time $\left(t\right)$ is given by the equation $t=\sqrt{x}+2$, where $x$ is in metres and $t$ in seconds. Find the work done by the force in first four seconds.

• A. $Zero$
• B. $2J$
• C. $4J$
• D. $8J$

Answer 1

Answer: (D)

$8J$

$x=(t-2{)}^2=t^2-4t+4$

$v=2t-4$

$a=2$

F=m.a.x

m=1kg

F=$2\times (4^2-4\times 4+4)=8J$