Acceleration of a car that goes from rest to 69 km h in 9 seconds

In summary, a car that goes from rest to 69 km/h in 9 seconds experiences an acceleration of approximately 7.67 m/s^2. This is a relatively fast acceleration and indicates a powerful engine and efficient transmission system. It also means that the car can reach high speeds in a short amount of time, making it suitable for quick acceleration situations such as passing other vehicles on the road.
  • #1
espo
the question what is the average acceleration of a car that goes
from rest to 69 km h in 9 seconds; don't i use the formula
a = vf-vi over t vf - 59 / 9 what is the correct final answer 16.5 km
 
Last edited by a moderator:
Physics news on Phys.org
  • #3
/h/s

Yes, you are correct in using the formula a = (vf - vi)/t to find the average acceleration of the car. To get the correct final answer, we need to first convert the initial and final velocities from km/h to m/s, since the unit for acceleration is m/s^2. This can be done by dividing them by 3.6. So, the initial velocity, vi, would be 0 m/s and the final velocity, vf, would be 19.17 m/s. Plugging these values into the formula, we get a = (19.17 m/s - 0 m/s)/9 s = 2.13 m/s^2. However, since the final answer is asked in km/h/s, we need to convert it back by multiplying by 3.6. So, the correct final answer would be 2.13 m/s^2 * 3.6 = 7.67 km/h/s. This means that the average acceleration of the car is 7.67 km/h/s from rest to 69 km/h in 9 seconds.
 

1. What is the formula for calculating acceleration?

The formula for acceleration is: a = (vf - vi) / t, where a is acceleration, vf is final velocity, vi is initial velocity, and t is time.

2. How do you convert km/h to m/s?

To convert km/h to m/s, you can use the formula: m/s = (km/h * 1000) / 3600. So in this case, 69 km/h would be equivalent to 19.17 m/s.

3. How long does it take for the car to reach 69 km/h from rest?

The car takes 9 seconds to reach 69 km/h from rest.

4. What is the average acceleration of the car?

The average acceleration of the car is 7.67 m/s^2.

5. How does the acceleration of this car compare to other cars?

The acceleration of this car is on the lower end compared to other cars. High-performance sports cars can have acceleration of 0-60 mph (0-96.6 km/h) in under 3 seconds, while average cars have acceleration of around 10 m/s^2.

Similar threads

  • Introductory Physics Homework Help
Replies
5
Views
974
  • Introductory Physics Homework Help
Replies
20
Views
891
  • Introductory Physics Homework Help
Replies
11
Views
637
  • Introductory Physics Homework Help
Replies
9
Views
2K
  • Introductory Physics Homework Help
Replies
15
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
1K
Replies
7
Views
3K
  • Introductory Physics Homework Help
3
Replies
94
Views
4K
Replies
7
Views
2K
  • Introductory Physics Homework Help
Replies
6
Views
625
Back
Top