Question

A car initially moving with a velocity 10 ms-1 is accelerated uniformly at the rate of 5 m s -2. In how much time will its velocity be 40 m s-1.

Answer 1

Explanation:

Initial Velocity (u) = 10 m/sec

Acceleration (a) = 5 m/sec

2

Distance (s) = 30 m

Final velocity (v) = ??

Using Newton's Third law of Motion,

v

2

=u

2

+2as

v

2

=10

2

+2×5×30

v

2

=100+300

v

2

=400

v =

400

v = 20 m/sec

Answer 2

Answer:

6 seconds

Explanation:

Using v=u+at

40=10+5×t

40-10=5t

30=5t

t= 30/5

t=6 seconds