Question

A bus starting from rest moves with a uniform acceleration of 0.1 m s-2 for 2
minutes. Find (a) the speed acquired, (b) the distance travelled

Answer 1

Solution

(a) Acceleration

The bus starts from rest.

Therefore, initial velocity (u) = 0 m/s

Acceleration (a) = 0.1 m.s-2

Time = 2 minutes = 120 s

Acceleration is given by the equation a=(v-u)/t

Therefore, terminal velocity (v) = (at)+u

= (0.1 m.s-2 * 120s) + 0 m.s-1

= 12m.s-1 + 0 m.s-1

Therefore, terminal velocity (v) = 12m/s

(b) As per the third motion equation,

Since a = 0.1 m.s-2, v = 12 m.s-1, u = 0 m.s-1, and t = 120s, the following value for s (distance) can be obtained.

Distance, s =(v2 – u2)/2a

=(122 – 02)/2(0.1)

Therefore, s = 720m.

The speed acquired is 12m.s-1 and the total distance travelled is 720m.

Answer 2

Explanation:

a=0.1m/s

2

and t=2min=120s

(A)v=u+at=0+0.1×120

⟹v=12m/s

(b)s=ut+

2

1

at

2

⟹s=0+

2

1

×0.1×(120)

2

⟹s=720m