Question

A large bus and a van, both moving with a velocity of magnitude v, have a head-on-collision and both the vehicles stop after the collision. If the time of the collision is 1 sec then :
(a) Which vehicle experiences smaller force of impact ?
(b) Which vehicle experiences the smaller momentum change ?
(c) Which vehicle experiences the greater acceleration ?
(d) Why does the bus suffer less damage than the van ?

CBSE Class IX Science LA (5 Marks)

Answer 1

 (a) Since the action and reaction are equal and opposite during a collision, both the vehicles experience an equal force.
(b) We are given,
Initial velocity of both the bus and the van = v
Final velocity of both the bus and the van = 0
 If m₁ and m₂ are the masses of the large bus and the van respectively, where m₁ is much greater than m₂
Change in momentum of the bus = m₁ x (0 — v) = —m₁v
Change in momentum of the van = m₂ x (0 — v) = —m₂v
Since m₁ < m₂, the van will experience smaller momentum change.
(c) The force acting on a body is equal to the product of its mass and the acceleration, i.e.,
                                  F= mass x acceleration = m x a
                                             a = F ÷ m
                                             a α 1 ÷ m
Acceleration experienced by the bus α 1 ÷ m₁
Acceleration experienced by the van , α 1 ÷ m₂
Since m₂ < m₁, therefore the van experiences greater acceleration.
(d) Due to the transfer of small momentum from the van to the bus, the bus suffers less damage than the van.

Answer 2

Answer:

a) both

b)van

c)bus

d) because of its force it will be truck