Sports car Acceleration problem

In summary, the acceleration of a sports car is much faster than a regular car due to powerful engines and lightweight bodies. Factors such as engine power, weight, and aerodynamics can affect the acceleration of a sports car. It can be measured using tools like a dynamometer or GPS-based performance meter. The acceleration can be improved through modifications, but this may also impact the car's overall performance and handling. Safety concerns should be taken into consideration when driving a sports car due to its high speeds and quick acceleration.
  • #1
JDR 007
13
0

Homework Statement



A sports car moving at constant speed travels 120 m in 4.7 s. If it then brakes and comes to a stop in 4.0 s, what is its acceleration? Express the answer in terms of g's, where g = 9.80 m/s2. (Take the positive direction to be the direction of travel.)

Homework Equations



Change in speed/time of change

The Attempt at a Solution


120/4.7=25.53m/s
end speed 0m/s-start speed 25.53m/s divided by time 4s= -6.38m/s^2 divided by 9.8m/s2= -.651 g

I got this wrong...what did I do wrong?
 
Last edited:
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  • #2
I think its probably because you forgot the minus sign. The question specifically states which direction is positive.
 
  • #3
Looks right to me.
 
  • #4
I used a minus sign...still wrong. It is a web based homework system and it is horrible. we have 4 trys to get it right...so i used a - sign then a + sign then scientific notation then changed my sig figs...so it says I am wrong but I don't see how.
 
  • #5
JDR 007 said:
I used a minus sign...still wrong. It is a web based homework system and it is horrible. we have 4 trys to get it right...so i used a - sign then a + sign then scientific notation then changed my sig figs...so it says I am wrong but I don't see how.

Double check that you posted the question exactly as it appears... you might have mixed up the numbers or something...
 
  • #6
I copy and pasted the question it is exact
 
  • #7
So the question gave g as 9.80m/s2? I'd have expected 9.81m/s2 if it was to two decimal places.
 
  • #8
I emailed my teacher And I will see what she says. I really hate these web assignments because they aren't multiple choice (hence wrong sigs, diff. calculators etc... will mess answers up due to rounding)
 
  • #9
A car slows down from 23 m/s to rest in a distance of 91 m. What was its acceleration, assumed constant?

I only have one more try on this one... is -2.91 right?
 
  • #10
JDR 007 said:
A car slows down from 23 m/s to rest in a distance of 91 m. What was its acceleration, assumed constant?

I only have one more try on this one... is -2.91 right?

Yes, that's what I get rounded to 2 decimal places.
 

1. How does the acceleration of a sports car compare to a regular car?

The acceleration of a sports car is typically much faster than that of a regular car. This is due to the fact that sports cars are designed with powerful engines and lightweight bodies, allowing them to reach high speeds more quickly.

2. What factors affect the acceleration of a sports car?

The acceleration of a sports car can be affected by a number of factors, including the power and torque of the engine, the weight and aerodynamics of the car, and the type of transmission and tires used.

3. How can the acceleration of a sports car be measured?

The acceleration of a sports car can be measured using a variety of methods, such as a dynamometer or a GPS-based performance meter. These tools can provide accurate measurements of acceleration time and speed.

4. Can the acceleration of a sports car be improved?

Yes, the acceleration of a sports car can be improved through various modifications such as upgrading the engine, reducing the weight of the car, and improving the aerodynamics. However, it is important to note that these modifications may also affect the overall performance and handling of the car.

5. Are there any safety concerns related to sports car acceleration?

Yes, sports car acceleration can pose safety concerns if not handled properly. The high speeds and quick acceleration of these cars require skilled drivers and proper safety precautions to ensure the safety of both the driver and others on the road.

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