Question

Rewrite the following table so as to match second and third column with the first column:

No.	Column 1	Column 2	Column 3
1.	Negative acceleration	Body has constant velocity.	A car initially at rest acquires velocity 50km/h in 10 second.
2.	Positive acceleration	Velocity of a body decreases.	A vehicle moving with velocity 25 m/s.
3.	Zero acceleration	Velocity of a body increases.	A vehicle moving with a speed of 10 m/s stops after 5 second.

Answer 1

No.	Column 1	Column 2	Column 3
1.	Negative acceleration	Velocity of a body decreases.	A vehicle moving with a speed of 10 m/s stops after 5 second.
2.	Positive acceleration	Velocity of a body increases.	A car initially at rest acquires velocity 50 km/h in 10 second.
3.	Zero acceleration	Body has constant velocity.	A vehicle moving with velocity 25 m/s.

Description:

(1) A vehicle moving with a speed of 10 m/s stops after 5 second.

Here, u = 10m/s, v = 0 (as vehicle comes to rest) and t = 5 s

Thus, velocity of the body decreases.

Using first kinematic equation,

v = u + at

⇒ 0 = 10 + 5a

⇒ a = −2 m/s²

Thus, negative acceleration is taking place.

(2) A car initially at rest acquires velocity 50 km/hr in 10 second.

Here, u = 0 (as car was initially at rest)

_{Thus, velocity of the body increases.}

t = 10 s

Using first kinematic equation,

v = u + at

⇒ 13.89 = 0 + 10 a

⇒ a = 1.39 m/s²

Thus, positive acceleration is taking place.

(3) A vehicle moving with velocity 25 m/s.

Here, u = 25 m/s

v = 25 m/s (as velocity is constant) t = for non-zero time

Using first kinematic equation,

v = u +at

⇒ 0 = 0 + at

⇒ a = 0 m/s²

Thus, no acceleration is taking place.