Question

8. The position x of a particle moving along X-axis at
time (t) is given by the equation t= VX + 2, where
x is in metres and t in seconds. Find the work
done by the force in first four seconds.
(1) Zero
(2) 2J
(3) 4J
(4) 8J​

Answer 1

Answer:

Here , we have been given an equation t=√x + 2.

Let's find X.

√X = t-2

X = (t - 2)^2

X = t^2-4t+4

Now let's find velocity.

v = dx/dt = 2t-4.

Put dx/dt = 0.

0=2t - 4

2t = 4

t = 2

By this way , we get the time at which the particle's velocity is zero.

We know,

a= dv/dt = 2

And

F = ma = 2m

and

x(initial) =( t-2)^2 = (4-2)^2 = 4 m

x (final) = 4 m

so displacement = 0 m

Work = Fd = 2m × 0 = 0

(a)Zero