Question

1. An object of mass 50 kg is accelerated uniformly from a
velocity of 4 ms to 8 msin 8 seconds. Calculate the
initial and final momentum of the object. Also find the
magnitude of the force exerted on the object.​

Answer 1

Answer :

Mass of object = 50kg

Initial velocity = 4m/s

Final velocity = 8m/s

Time interval = 8s

We have to find

• Initial momentum
• Final momentum
• Magnitude of force exerted on the object

⧪ Momentum of body is measured as the product of its mass and velocity$.$

• p = mass × velocity

★ Initial momentum :

➠ p₁ = m × u

➠ p₁ = 50 × 4

➠ p₁ = 200 N s ___ (I)

★ Final momentum :

➠ p₂ = m × v

➠ p₂ = 40 × 8

➠ p₂ = 320 N s ___ (II)

⧪ As per newton's second law of motion, force is defined as the rate of change of linear momentum.

• F = ∆p/∆t

➙ F = (p₂ - p₁)/∆t

➙ F = (320 - 200)/8

➙ F = 120/8

➙ F = 15 N ___ (III)