Question

The displacement in metres of a body varies with time t in seconds as y = t^2 - t - 2 . The displacement is zero for a positive of t equal to​

Answer 1

Given:

The displacement in meters of the body as a function of time y = t² -t -2

To find:

Where the displacement equals to 0 for a positive t.

Solution:

The displacement is given as:

y = t² -t -2

We need to find when y=0

So putting y=0, we get:

t² -t- 2= 0

t² -2t +t -2 =0

t(t - 2) + 1(t - 2) =0

(t - 2)(t + 1) = 0

t = 2, t = -1

Since t needs to be positive, therefore we will consider t=2 sec.

Therefore the displacement is 0 at t= 2 sec.

Answer 2

Answer:

v=dx/dt=d/dt[t^2-t-2]

2(t)-1

v(t)=2t-1

1=2t

t=1/2

t=0.5sec