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A small car makes a head-on collision with a large truck on an icy pavement. Bef

ID: 1434592 • Letter: A

Question

A small car makes a head-on collision with a large truck on an icy pavement. Before they collide, they were traveling with the same speed (but in opposite directions). During the collision, which vehicle experiences the greater collision force? During the collision, which vehicle experiences the greater acceleration? Which vehicle had the larger change in momentum? Which vehicle had the larger change in velocity? Assuming the car driver and the truck driver have the same mass, which driver experiences the greater force during the collision? A car, traveling at a speed of 10 m/s (22 mph) makes a head-on collision with a tree. Thanks to the "crumple zone" engineered in modem cars, the car decelerates (from 10 m/s to zero) as the front of the car crumples over an approximate 1-meter distance. What is the change in the momentum of the 75-kg driver? Assuming uniform deceleration, how much time elapses during the deceleration? What is the average force acting on the driver, assuming the driver is wearing his seatbelt, so he also decelerates from 10 m/s to zero over the same 1-meter distance. What would be the average force on the driver if he did not wear his seatbelt, and was stopped in a 0.5-cm distance by the tree itself?

Explanation / Answer

1)

a) Using third law of motion

For every action, there is an equal and opposite reaction.

hence , both car and truck experiences same collision force.

b)

as the mass of car is less and force is same on both.

the car will experience the greater acceleration.

c)

as change in momentum = force * time

as force and time is same for both

the change in momentum is same for both

d)

as the car has smaller mass

the change in velocity of car will be larger.

e)

as the acceleration of car is higher ,

for the same mass

the driver of car will experience higher force