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# Physics/acceleration due to gravity in car

Question
Sir I have a maruti800 car there are 4 wheels 12" each and final speed is 39.88m/s I want to know accleration due to gravity for this in % and provide me formula for this also.

Hello vinu,

Acceleration is the rate of change of velocity per unit of time. You didn't give me enough data to calculate acceleration. If you started from a velocity of 0 and accelerated to 39.88 m/s and recorded the time, t, in seconds to accomplish that, then
Average acceleration = (39.88 m/s - 0 m/s) / t
The result of that calculation would be in units of m/s^2. As an example, assume it took you 12 seconds, then
Average acceleration = (39.88 m/s - 0 m/s) / 12 s = 7.33 m/s^2

To convert to a comparison to the acceleration due to gravity, divide by the value of the acceleration due to gravity which is 9.8 m/s^2. Continuing the above example, where the calculation gave you 7.33 m/s^2, you would see that
comparison to the acceleration due to gravity = (7.33 m/s^2) / 9.8 m/s^2 = 0.75
Or 75%. The usual way to give the acceleration as compared to the acceleration due to gravity would be 0.75g.

But there may be a difference between average acceleration and what you wanted. Typically, acceleration is greatest in the first second of a car's acceleration. As wind resistance increases and gear ratio decreases, the car's acceleration would decrease significantly.

I hope this helps,
Steve

Physics

Volunteer

#### Steve Johnson

##### Expertise

I would be delighted to help with questions up through the first year of college Physics. Particularly Electricity, Electronics and Newtonian Mechanics (motion, acceleration etc.). I decline questions on relativity and Atomic Physics. I also could discuss the Space Shuttle and space flight in general.

##### Experience

I have a BS in Physics and an MS in Electrical Engineering. I am retired now. My professional career was in Electrical Engineering with considerable time spent working with accelerometers, gyroscopes and flight dynamics (Physics related topics) while working on the Space Shuttle. I gave formal classroom lessons to technical co-workers periodically over a several year period.

Education/Credentials
BS Physics, North Dakota State University
MS Electrical Engineering, North Dakota State University