Question

A bus starting from rest moves with a uniform acceleration of 0.1 ms-2 for 2 minutes. find.
(a) the speed acquired.
(b) the distance travelled​

Answer 1

Answer:

v= u +at

here the initial vel. is 0

therefore,....0+0.1 ×120 .....(2mins ×60sec=120 mins)

0+12=12

12m/s is the speed .

Answer 2

[a]

GIVEN :-

• Initial velocity , u = 0 m/s. [ Bus starting from rest ]
• Acceleration , a = 0.1 m/s²
• Time , t = 2 minutes.

TO FIND :-

• The speed acquired , v.

SOLUTION :-

★ Firstly we will convert the given time into seconds because the SI unit of time is second.

→ 1 minute = 60 seconds.

→ 2 minutes = 120 seconds

AS we know that the formula for Acceleration,

→ Acceleration = change in velocity/Time

→ a = (v - u)/t

→ 0.1 = (v - 0)/120

→ v - 0 = 0.1 × 120

→ v - 0 = 12

→ v = 12 + 0

→ Final velocity = 12 m/s

Hence the speed acquired in first case is 12 m/s.

[b]

GIVEN :-

• Initial velocity , u = 0 m/s. [ Bus starting from rest ]
• Acceleration , a = 0.1 m/s²
• Time , t = 2 minutes.
• Final velocity , v = 12 m/s.

TO FIND :-

• The distance travelled , s.

SOLUTION :-

★ By using third equation of motion ★

→ v² - u² = 2as

• v = Final velocity.
• u = initial velocity.
• a = acceleration.
• s = distance travelled.

→ (12)² - (0)² = 2 × (0.1) × s

→ 144 - 0 = 0.2s

→ 144 = 0.2s

→ s = 144/0.2

→ Distance travelled = 720 m.

Hence the Distance travelled in second case is 720 m.