Question

A car initally at rest accelerates in a straight line at 3 m/s2 what will be its speed after 2 seconds

Answer 1

In this Question we have given

acceleration, a=3m/s^2

and time, t=2s

we have to find speed, v=?

Apply newton's Ist equation of motion which goes as

`[tex]v =u + at\\ Here   v  is final velocity\\u - initial velocity\\a-acceleration\\t- time`[/tex]

In this problem the car starts from rest it means initial velocity, u =0.

Putting values of u, a and t in first equation of motion

`v=0+3*2\\v=6m/s`

Therefore speed of car after 2 second will be 6m/s

Note: In this type of problems. First check the units of all quatities. As all the quantities must be first changed into matching units i.e cgs or s.i. units before applying the equation.