A large truck and a car both moving with a velocity of magnitude v, have a head-on collision and both of
them come to a halt after that if the collision lasts for 1s:
a) Which vehicle experiences the greater force of impact?
b) Which vehicle experiences the greater change in momentum?
c) Which vehicle experiences the greater acceleration?
d) Why is the car likely to suffer more damage than the truck?
Answers
Explanation:
Let mass of truck = M
mass of car = m
velocity of truck = V
then, velocity of car = - V { because both are moving in opposite direction}
external force = 0
we know, according to 2nd Law of motion , if external force is equal to zero then, linear momentum will be conserved.
and also we know, according to 3rd Law of motion " action and reaction are of equal magnitude and directed in opposite directions "
(a) so , according to " 3rd Law of motion ". both experience equal magnitude of force .
(b) due to "conservation of Linear momentum " , both have same change in momentum .
(c) acceleration depends upon mass of body , and it is inversely proportional to mass . so, acceleration of car is greater then truck .
(d) due to acceleration of car is higher then truck .
Answer:
(a) During head on collision forces applied by truck and car are action reaction forces. Hence both vehicles experience same (equal) force of impact.
(b) Here initial velocity of both car and truck is same equal to v and final velocity of both is zero. But mass of truck is much more than that of car, hence change in momentum of truck is more than change in momentum of car.
(c) For same force of impact, the acceleration of car will have greater magnitude because its mass is less.
(d) Car suffers more damage than the truck, as acceleration of car is more, its velocity falls to zero in a shorter time and consequently, its momentum changes in a shorter time.