What is the average acceleration of the Nissan Leaf in m/s/s?

[connphysics]

Although Nissan hasn't advertised it, other sources report that the Nissan Leaf electric car can accelerate from 0 to 60 mph in 9.9 seconds. Assuming THIS data is correct, What is the AVERAGE acceleration of the Leaf in m/s/s ? (meters per second squared) ?

I know I should be using Vf-Vi / t ?

helppp

 

[sophiecentaur]

Hi
You have the right formula. Just convert mph to metres per second and bob's yer uncle.

 

[connphysics]

ok...I think I just did...and I got an average accel of 2.709 m s s ...sound right to you ?

 

[olivermsun]

First make sure you're using compatible units, and then the problem almost solves itself.

 

[connphysics]

i got it thanks ! one more question - if a cars mass is 1604 kg and it is traveling at a speed of 60 mph ...then it's KE is .5 X 1604 X 60 squared = a KE of 2,88,200 J ...now...my question is...using the work energy theorem - what is the TOTAL WORK done to get to a speed of 60 mph ??

 

[sophiecentaur]

The useful work is the same as the final KE so you've done that already. The actual work would be a lot more than that. Efficiency comes into it but it's hard to estimate that.

 

[connphysics]

so...the TOTAL work would be 2,887,200 J ?

 

[connphysics]

the total work to get to a speed of 60 mph ?

 

[sophiecentaur]

That is the definition of useful work done on the car. I was being a bit of a smartarse there; I said nothing about air resistance or friction. That's another can of worms. To work that out you'd either need to have some way of measuring the torque from the engine and to integrate torque times revs from 0 to 60. or to look at the engine characteristics under the various speeds and loads and the drag factor of the car body at various speeds. That would be a lot lot more, of course. Definitely not trivial.

 

[connphysics]

ahh..I see...yeah...not trivial at all ;) Centaur - one final question for you ...how can I calculate the AVERAGE power during the acceleration of 9.9 s ?

 

[sophiecentaur]

Same problem as before, I think. "Useful power" would be your KE/9.9s

Hang on . . . . where did you get that figure for KE from? You seem to have used mph and not m/s. That's not on, I'm afraid, if you want the answer to be in J.

Units, Units, Units all the way.