Momentum and Impulse on a car

In summary, momentum is a measure of an object's motion, determined by its mass and velocity. A car's momentum is directly related to its speed and mass. Impulse is the change in momentum of an object, calculated by multiplying the force applied to an object by the time it is applied for. When a car experiences a change in momentum, it is also experiencing an impulse. Understanding these principles can help engineers design safer cars, with features such as airbags and crumple zones to absorb and reduce the effects of momentum and impulse during accidents.
  • #1
Shatzkinator
53
0

Homework Statement


A 7.0 kg toy car can move along an x axis; Figure gives Fx of the force acting on the car, which begins at rest at time t=0. The scale on the Fx axis is set by Fxs = 6.0 N. In unit-vector notation, what is p at (a)t = 1.0 s and (b)t = 6.0 s,(c) what is v at t = 9.0 s?

http://edugen.wiley.com/edugen/courses/crs1650/art/qb/qu/c09/q30.jpg

Homework Equations


p = mv
F = ma
J = Ft
V2 = v1 + at


The Attempt at a Solution



I tried solving for V2 using F = ma
f = m(v2-v1/t)
6 = 7 (v2 - 0/1)

then i plugged this value into p = mv but then i realized they want unit vector notation and I got really confused! =S
 
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  • #2
Difficult to tell what is going on without the diagram.
 
  • #3
You are dealing with a force that is not constant. The easiest way to deal with this is to remember the change in momentum is equal the the integral of the force with respect to time. I.e. the area under your force curve.
 
  • #4
Delphi51 said:
Difficult to tell what is going on without the diagram.

I see a diagram. Sometimes. It does seem to come and go. When I first open the page it's there. If I refresh the page it disappears. I'm using Firefox on Ubuntu. Hmm. Now it seems to be gone completely. Too bad. It was a nice diagram.
 
Last edited:

What is momentum?

Momentum is a measure of an object's motion, determined by its mass and velocity. It is represented by the equation p = m x v, where p is momentum, m is mass, and v is velocity.

How is momentum related to a car's motion?

A car's momentum is directly related to its speed and mass. The more mass a car has, the more momentum it will have at a given speed. Similarly, the faster a car is moving, the more momentum it will have.

What is impulse?

Impulse is the change in momentum of an object. It is calculated by multiplying the force applied to an object by the time it is applied for. The equation for impulse is J = F x t, where J is impulse, F is force, and t is time.

How does impulse affect a car's motion?

When a car experiences a change in momentum, it is also experiencing an impulse. This can happen when the car is accelerating, braking, or colliding with another object. The greater the impulse, the greater the change in momentum, and thus the greater the effect on the car's motion.

How can momentum and impulse be used to improve car safety?

Understanding the principles of momentum and impulse can help engineers design safer cars. By considering factors such as mass, velocity, and force, they can create cars that are less likely to experience dangerous changes in momentum or impulse during accidents. Safety features such as airbags and crumple zones are also designed to absorb and reduce the effects of momentum and impulse on passengers in a crash.

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