Finding the Force of air resistance

[scytherz]

A 1967 Corvette has a weight of 3020 lbs. The 427 cu-in engine was rated at 435 hp at 5400 rpm. a) If the engine used all 435 hp at 100% efficiency during acceleration, what speed would the car attain after 6 seconds? b) What is the average acceleration? (in “g”s).

ans...
a) 120 mph b) 0.91g.



If someone knew how to approach this problem, kindly tell to me... Since I've tried different approaches, (Finding the Force of air resistance, rolling friction, Fuel consumption, substituting the energy used by the gasoline as the kinetic energy, .. But still didnt found the answer,... its almost 1 and half a week, trying to solve this problem,... and I think my approach is going way off...

Relevant Equations:

P = W/t
K=1/2mv^2
1 hp = 746 W = 550 ft lb/s
1 L = 3.5x10^7


The attempt at solution

since the car uses 427 in^3 engine(6.997 L), since 1L of using gasoline is 3.5x10^7, so the energy used is 244 895 000 j divide by 6 s, is 40 815 833.33j/s subtracted by the 435/6 hp, ans 40761 748.33 j/s... using the formula for Kinetic energy, K= 1/2mv2, I got 243 m/s... which is wrong...


I also tried using P = W/t , by finding the work, w= pt, w= 1 947 060 Nm, then substitute on k= mv^2, but still wrong...

 

[Redbelly98]

At a power of 435 hp, how much energy is produced in 6 seconds?

 

[scytherz]

thats 2610 Hp or 1 947 060 Nm and substitute to energy... I ve tried that, and still got the wrong answer, my hunch is that we should utilize the given ( the 427 cu in engine) but tried it an still got the wrong answer... btw the answer on that one is 54 mph...

 

[Redbelly98]

If you can show your full calculation, I might be able to spot what went wrong.

BTW, I am getting 53 m/s or 119 mph.

 

[scytherz]

If you can show your full calculation, I might be able to spot what went wrong.

BTW, I am getting 53 m/s or 119 mph.

yeah I got it! Thank you very much!... I didn't know It was that easy, I wasted a week trying to solve this tricky problem...