Question

The particle is moving with uniform acceleration along a straight line.The velocity of a particle at an instant is 20 m/s.After 4 s,its velocity will become 27 m/s.The velocity at 3 s before the given instant is

• A. 14.75 m/s
• B. 16.5 m/s
• C. zero
• D. 7 m/s

Answer 1

The correct option is A 14.75 m/s

Acceleration = (v - u) / t

= (27 - 20) / 4

=1.75 m/s²

Acceleration of body is 1.75 m/s²

Now,

v = u + at

20 = u + (1.75 × 3)

u = 20 – 5.25

u =14.75 m/s

Velocity 3 seconds before was 14.75 m/s