Verified answer

Answer

Initial momentum = 40 kg.m/s

Final momentum = 80 kg.m/s

Magnitude of force = 8 N

Given

Mass of a body , m = 10 kg

Initial velocity , u = 4 m/s

Final velocity , v = 8 m/s

Time , t = 5 s

To Find

a . Momentum before the action of force

b . Momentum after the action of force

c . Magnitude of force

Formula Applied

Momentum is defined as product of mass and velocity'

where ,

• P denotes momentum
• m denotes mass
• v denotes velocity

Force is defined as product of mass and acceleration

where ,

• F denotes force
• m denotes mass
• a denotes acceleration

Solution

a . Momentum before the action of force

velocity before action of force is ,

Initial velocity , u = 4 m/s

mass , m = 10 kg

Initial Momentum , P = ? kg.m/s

So ,

⇒ P = mu

⇒ P = (10)(4)

⇒ P = 40 kg.m/s

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b . Momentum after the action of force

Velocity after action of force is ,

Final velocity , v = 8 m/s

Mass , m = 10 kg

Final Momentum , P = ? kg.m/s

So ,

⇒ P = mv

⇒ P = (10)(8)

⇒ P = 80 kg.m/s

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c . The magnitude of force

Acceleration is defined as rate of change in velocity .

Now ,

So , Magnitude of the force = 8 N

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