Question

. A car of mass 1200kg is moving with a velocity of 108km/h. On applying brakes, its velocity is reduced to 36km/h. Find the change in momentum.​

Answer 1

Answer:

change in momentum

= mv - mu

=> 1200(36 - 108)

=> 1200 × 72

=> - 86400 kg m/sec

Answer 2

Given :

▪ Mass of car = 1200kg

▪ Initial velocity = 108kmph

▪ Final velocity = 36kmph

To Find :

✴ Change in momentum.

Concept :

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

↗ It is a vector quantity.

↗ It has both magnitude as well as direction.

↗ SI unit : kg m/s OR Ns

Conversion :

❇ 1kmph = 5/18mps

❇ 108kmph = 108×5/18 = 30mps

❇ 36kmph = 36×5/18 = 10mps

Calculation :

Initial Momentum :

☞ Pi = m × u

☞ Pi = 1200 × 30

☞ Pi = 36000Ns

Final Momentum :

☞ Pf = m × v

☞ Pf = 1200 × 10

☞ Pf = 12000Ns

Change in Momentum :

→ ΔP = | Pf - Pi |

→ ΔP = | 12000 - 36000 |

→ ΔP = | -24000 |

→ ΔP = 24 kNs ✔