Impulse and Momentum of an auto

In summary, an automobile with a mass of 2300 kg and a velocity of +16 m/s collides with a stationary car with a mass of 1800 kg, causing both cars to skid together with locked wheels. The velocity after the collision is 9 m/s and the impulse acting on the cars is -36800 Ns. With a coefficient of kinetic friction of 0.80, the cars skid a distance of 5.2 meters before coming to a rest. The acceleration due to friction is determined by the formula ug - a = a, with the coefficient of friction being 0.8 for both cars.
  • #1
kaspis245
189
1

Homework Statement


An automobile has a mass of 2300 kg and a velocity of
+16 m/s. It makes a rear-end collision with a stationary car
whose mass is 1800 kg. The cars lock bumpers and skid off
together with the wheels locked. (a) What is the velocity of the
two cars just after the collision? (b) Find the impulse (magnitude
and direction) that acts on the skidding cars from just after the col-
lision until they come to a halt. (c) If the coefficient of kinetic fric-
tion between the wheels of the cars and the pavement is
0.80, determine how far the cars skid before coming to rest.

a) v = 9 m/s
b) FΔt = -36800 Ns

I need to find only the c part of the problem.

Homework Equations


The Principle of Conservation of Linear Momentum

The Attempt at a Solution


image.jpg


The answer must be s = 5.2 m
 
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  • #2
Where did the formula ug - a = a come from? The coef of friction between the cars and the pavement is 0.8. Both cars. So what acceleration do the cars experience due to friction? Yes, it really is that simple.
 

1. What is the difference between impulse and momentum?

Impulse and momentum are related concepts in physics, but they have different definitions. Momentum is a measure of an object's mass and velocity, while impulse is a measure of the change in an object's momentum over time. In simpler terms, momentum is the amount of "oomph" an object has, while impulse is the force applied to change that "oomph."

2. How is impulse related to the motion of an auto?

In the context of an auto, impulse is the force applied to change the car's momentum. This can happen in several ways, such as when the car accelerates, brakes, or collides with another object. The amount of impulse applied to the car will determine how much its momentum changes, and therefore how its motion is affected.

3. What factors affect the impulse and momentum of an auto?

There are several factors that can affect the impulse and momentum of an auto. These include the mass of the car, its velocity, the force applied to it, and the duration of that force. Additionally, external factors such as friction and air resistance can also impact the impulse and momentum of an auto.

4. How is the impulse-momentum theorem used in analyzing auto collisions?

The impulse-momentum theorem is a fundamental principle in physics that states that the change in an object's momentum is equal to the impulse applied to it. In the context of auto collisions, this theorem can be used to analyze the forces involved and determine the resulting change in momentum for each vehicle involved.

5. Can impulse and momentum be conserved in an auto collision?

In a perfectly elastic collision, where no energy is lost, both impulse and momentum can be conserved. This means that the total momentum of the system before and after the collision will be the same, and the total impulse applied to the system will also be the same. However, in most real-life scenarios, energy is lost during a collision, making it difficult to conserve both impulse and momentum.

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