Question

A body of 20 kg mass is moving with 30 m/s. Its velocity increases to 60 m/s in 10 seconds.
Find its acceleration, change in momentum of body and external force required for this change.

Answer 1

Given:

A body of 20 kg mass is moving with 30 m/s. Its velocity increases to 60 m/s in 10 seconds.

To find:

• Acceleration
• Change in momentum
• External force needed

Calculation:

• Let acceleration be 'a'.

a = (v - u)/t

=> a = (60 - 30)/10

=> a = 30/10

=> a = 3 m/s².

• Let momentum change be ∆P.

∆P = m × ∆v

=> ∆P = 20 × (60 - 30)

=> ∆P = 20 × 30

=> ∆P = 600 kg m/s.

• Let force needed be 'F'

F = m × a

=> F = 20 × 3

=> F = 60 N.

$\star$ Hope It Helps.

Answer 2

Explanation:

Given:

A body of 20 kg mass is moving with 30 m/s. Its velocity increases to 60 m/s in 10 seconds.

To find:

• Acceleration
• Change in momentum
• External force needed

Calculation:

• Let acceleration be 'a'.

a = (v - u)/t

=> a = (60 - 30)/10

=> a = 30/10

=> a = 3 m/s².

Let momentum change be ∆P.

∆P = m × ∆v

=> ∆P = 20 × (60 - 30)

=> ∆P = 20 × 30

=> ∆P = 600 kg m/s.

Let force needed be 'F'

F = m × a

=> F = 20 × 3

=> F = 60 N.