Impulse for a car when it drives in a circle

Click For Summary

Homework Help Overview

The problem involves a 1400 kg car driving at a constant velocity of 5.3 m/s, making a 90-degree turn over 4.6 seconds, and then colliding with a tree, taking 350 ms to stop. The questions focus on calculating the impulse during the turn and the collision, as well as the average force during these events and the angle of the force.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to calculate impulse and force but expresses uncertainty about the implications of the car's constant velocity during the turn.
  • Some participants question the assumptions regarding forces acting on the car during the turn, particularly in the context of uniform circular motion.
  • Others suggest that the time and tangential speed can be used to find the radius of the turn, which may help in further calculations.

Discussion Status

The discussion is ongoing, with participants exploring the implications of uniform circular motion and the relationships between time, speed, and radius. Some guidance has been offered regarding the relationship between the given parameters, but no consensus has been reached on the calculations.

Contextual Notes

Participants note the absence of the radius of the turn, which is crucial for applying uniform circular motion formulas. The original poster also indicates a lack of clarity on how to approach the problem.

iamhe
Messages
6
Reaction score
0

Homework Statement


A 1400kg car is driving at a constant velocity, 5.3 m/s. It turns 90 degrees in 4.6 seconds. And then it slams into a tree and it takes 350 ms to stop the car.
What is the impulse on the car (a) due to the turn? (b)Due to the collision with the tree?
What is the magnitude of the average force that acts on the car (c)during the turn? (d)During the collision with the tree?
What is the angle between the average force in (c) and the positive x direction?


Homework Equations


Impulse = j = p2-p1 = mv2-mv1
F = ma


The Attempt at a Solution


a) 0. Since the velocity does not change, and the mass is constant, there is no change between p1 and p2.
b) j = (1400)(5.3) - (1400)(0) = 7420
c) F = 0/(4.6) = 0
d) F = (7420)/(0.350) = 21200
e) I have absolutely no clue on how to even start this one.


Thanks in advance for any help!
 
Physics news on Phys.org
Well for the parts where the car is making the turn, there's a force that you might be forgetting about. Basically, during the turn, the car is in Uniform Circular Motion for a quarter of a circle.
 
If I am not given the radius of the turn, how can I still use the uniform circular motion formula?
 
You're given the time it took to make a quarter of a circle and you're given the tangential speed during the turn. There's a relationship between those that will give you the radius.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
7K
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
5K
  • · Replies 8 ·
Replies
8
Views
3K
Replies
3
Views
5K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
11K
  • · Replies 1 ·
Replies
1
Views
9K