Question

What is the change in momentum of a car weighing 1500 kg when is speed increases from 36 kilometre per hour to 72 km per hour uniformly

Answer 1

p=m∆v here v1= 36km/hr (10m/sec), V2= 72km/hr(20m/sec), p= 1500×(20-10) , p= 15000kg.m/sec

Answer 2

Given :

▪ Mass of the car = 1500kg

▪ Initial velocity = 36kmph

▪ Final velocity = 72kmph

To Find :

▪ Change in momentum of car.

Concept :

→ Momentum is defined as the product of mass and velocity.

→ Momentum is a vector quantity.

→ It has both magnitude as well as direction.

Mathematically,

$\bigstar\:\underline{\boxed{\bf{\red{P=mv}}}}$

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

Conversion :

✏ 1kmph = 5/18mps

✏ 36kmph = 36×5/18 = 10mps

✏ 72kmph = 72×5/18 = 20mps

Calculation :

→ Pi = m(vi)

→ Pi = 1500×10

→ Pi = 15,000 Ns

☞ Pf = m(vf)

☞ Pf = 1500×20

☞ Pf = 30,000 Ns

→ ΔP = Pf - Pi

→ ΔP = 30,000 - 15,000

→ ΔP = 15,000 Ns

→ ΔP = 15 kNs