Question

A bus starting from rest masses with a uniform acceleration of 2 m/s for 4 minutes. a)find the speed acquired. b)find the distance travelled ​

Answer 1

Answer:

Given :

Initial velocity, u = 0 m/s (as it is starting from rest)

Acceleration, a = 2 m/s²

Time, t = 4 minutes

To find :

Speed acquired, v

Distance travelled, s

According to the question,

Note :

1 minute = 60 seconds

4 minutes = 4 × 60 = 240 seconds

By using Newtons first equation of motion,

➞ v = u + at

Where,

v = Final velocity

u = Initial velocity

a = Acceleration

t = Time

➞ Substituting the values,

➞ v = 0 + 2 × 240

➞ v = 0 + 480

➞ v = 480

So,the speed acquired is 480 m/s.

Now,

By using Newtons third equation of motion,

➞ s = ut + ½ at²

Where,

s = Distance

u = Initial velocity

a = Acceleration

t = Time

➞ Substituting the values,

➞ s = 0 × 240 + ½ × 2 × 240 × 240

➞ s = 0 + 57600

➞ s = 57600

So,the distance travelled is 57600 meters.

Explanation:

Answer 2

Answer :

(a) Initial speed of the bus, u = 0

Acceleration, a = 0.1 m/s2

Time taken, t = 2 minutes = 60 x 2 = 120 s

Let v be the final speed acquired by the bus.

v = u + at = 0 + 0.1 x 120 = 12 m/s

∴ The speed acquired by the bus is 12 m/s

(b) According to the equation of motion:

v2 = u2 + 2as

v2 − u2 = 2as

(12)2 - (0)2 =2(0.1)s

144 = 0.2 s

s = 144 / 0.2

s = 720 m

Distance travelled by the bus is 720 m.

Hope it helps you.....