Question

1.) A bus is moving with an initial velocity 10 m/s after 2 seconds, The velocity becomes 20m / s find the acceleration and distance taken by the bus.​

Answer 1

GIVEN :-

• Initial velocity (u) = 10m/s
• Final velocity (v) = 20m/s
• Time taken (t) = 2s

TO FIND :-

• Acceleration (a).
• Distance (s).

TO KNOW :-

★ 1st Kinematical equation,

• v = u + at

★ 3rd Kinematical equation,

• v² = u² + 2as

SOLUTION :-

By 1st Kinematical equation,

♦ v = u + at

• v = 20m/s
• u = 10m/s
• t = 2s

Putting values,

→ 20 = 10 + a(2)

→ 20 - 10 = 2a

→ 10 = 2a

→ a = 10/2

→ a = 5m/s²

Acceleration of the bus is 5m/s².

Now , By 3rd Kinematical equation,

♦ v² = u² + 2as

• v = 20m/s
• u = 10m/s
• a = 5m/s²
• s = ?

Putting values,

→ 20² = 10² + 2(5)(s)

→ 400 = 100 + 10s

→ 400 - 100 = 10s

→ 300 = 10s

→ s = 300/10

→ s = 30m

Hence , acceleration of bus is 5m/s² and it covered 30m.

MORE TO KNOW :-

1) 2nd Kinematical equation,

• s = ut + (1/2)at²

2) Kinematical equations are only applicable when acceleration is constant.