Calculating Acceleration of a Car After Braking

  • Thread starter IDespisePhysics
  • Start date
  • Tags
    Acceleration
In summary, the problem involves a car traveling at 95 km/hr and coming to a stop in 60 meters. The given information includes the distance, initial velocity, and final velocity. The correct formula to use is vf^2=vi^2+2ax, and after converting units, the answer is -5.81m/s^2.
  • #1
IDespisePhysics
10
0

Homework Statement


A car is traveling at 95 km/hr. The driver steps on the brakes and the car comes to a stop in 60 meters. What is the car's acceleration?

Homework Equations


My issue might be which formula is correct but, I believe I would use, vf^2=vi^2+2ax

The Attempt at a Solution


Every time I begin any problem I write down the givens.
d= 60 meters
Vi= 95 km/hr
Vf= 0 m/s
Are my givens wrong? If not, I've continued to plug it in into the problem above. I assume I'm using Kinematics and since the other equations require 't' or time, I don't believe I use those equations for this problem. As I plug the givens into the equation above, the math doesn't add up to the answer my teacher had said it was; which is -5.81m/s^2.
 
Physics news on Phys.org
  • #2
Would I have to convert the 95 km/hr?
 
  • #3
IDespisePhysics said:
Would I have to convert the 95 km/hr?
That is one of your first steps to convert it out to get similar units.
 
  • #4
Thank you! I got the answer now! :D
 
  • #5
IDespisePhysics said:
Thank you! I got the answer now! :D
Happy to help :-)
 

1. How do you calculate the acceleration of a car after braking?

To calculate the acceleration of a car after braking, you will need to know the initial velocity (speed) of the car before braking, the final velocity of the car after braking, and the time it took for the car to come to a complete stop. The formula for acceleration is final velocity minus initial velocity divided by time. For example, if a car's initial velocity was 50 mph and it took 5 seconds to come to a complete stop, the acceleration would be (0 mph - 50 mph) / 5 seconds = -10 mph/s.

2. What factors can affect the acceleration of a car after braking?

The acceleration of a car after braking can be affected by several factors, including the initial speed of the car, the braking force applied, the weight and size of the car, the condition of the road surface, and any external forces acting on the car, such as wind resistance or friction from the tires.

3. Can the acceleration of a car after braking be negative?

Yes, the acceleration of a car after braking can be negative. This indicates that the car is decelerating or slowing down. The sign of the acceleration (positive or negative) depends on the direction of the final velocity compared to the initial velocity. A negative acceleration can also be referred to as a deceleration or negative acceleration.

4. How does the acceleration of a car after braking affect the distance it takes to stop?

The acceleration of a car after braking directly affects the distance it takes to stop. The greater the acceleration, the shorter the stopping distance will be. This is because a larger acceleration means the car is slowing down more quickly. The opposite is also true - a smaller acceleration will result in a longer stopping distance.

5. Can the acceleration of a car after braking be greater than the acceleration before braking?

No, the acceleration of a car after braking cannot be greater than the acceleration before braking. This is because the car is slowing down and therefore the acceleration is decreasing. The maximum acceleration of a car is typically achieved before braking, when the car is accelerating at full speed.

Similar threads

Distance travelled by a car considering only air friction?
    • Introductory Physics Homework Help
Replies
4
Views
921
Relating acceleration to distance and time
    • Introductory Physics Homework Help
Replies
5
Views
1K
Why do I keep getting friction coefficient as a negative?
    • Introductory Physics Homework Help
Replies
17
Views
831
Solving a V-vs-s Problem: John's Quandry
    • Introductory Physics Homework Help
Replies
11
Views
672
"How far did the car move while braking?"
    • Introductory Physics Homework Help
Replies
14
Views
2K
Help with question on motion: Avoiding a rear-end collision
    • Introductory Physics Homework Help
Replies
6
Views
723
Elastic Collision troubles...
    • Introductory Physics Homework Help
Replies
20
Views
972
Acceleration required for ship to avoid crashing into another ship
    • Introductory Physics Homework Help
Replies
15
Views
1K
Kinematics: Motion in One Direction: Car Chase
    • Introductory Physics Homework Help
Replies
9
Views
2K
Reaction time while stopping a car
    • Introductory Physics Homework Help
Replies
29
Views
2K

Hot Threads

Recent Insights

Back
Top