Question

8. A truck travelling at 25m/s puts its brake on for 4s. this produces a retardation of 2/s2. What does the truck velocity drop to?

Answer 1

Answer:

Given:

Initial velocity = 25m/s

Acceleration = -2m/s^2

Time = 4 sec

To Find :

Final velocity

Solution:

using first equation of motion-

v=u+at

》 v = 25 + (-2)×4

》 v = 25-8

》 v= 17 m/s

Answer 2

Given ,

Initial velocity (u) = 25 m/s

Time (t) = 4 s

Retardation (a) = - 2 m/s²

We know that , the first equation of motion is given by

$\large \sf \fbox{v = u + at}$

Thus ,

$\Rightarrow \sf v = 25 + ( - 2) \times 4 \\ \\\Rightarrow \sf v = 25 - 8 \\ \\ \Rightarrow \sf v = 17 \: \: m/s$

$\therefore \sf \underline{\bold{The \: initial \: velocity \: is \: 17 \: m/s}}$