Frictional force of car homework

AI Thread Summary
The discussion revolves around a physics homework problem involving a dragster's acceleration and the calculation of frictional force. The dragster accelerates from rest to 350 km/h in 6.2 seconds, with a mass of 800 kg and a driving force of 14,000 N. The user calculates the net force and finds a frictional force of -1,440 N, which is incorrect according to the provided solution of 10,900 N. The error lies in the misunderstanding of how to calculate the net force and friction, leading to confusion about the relationship between applied and frictional forces. Clarification on the correct approach to solving the problem is needed.
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Homework Statement



A dragster reaches 350km/h from rest to 6.2s. If the car is 800kg and generates a driving force of 14000N, find the force of friction acting on the car.

Homework Equations





The Attempt at a Solution



350km/h = 97.2m/s

a=\frac{97.2m/s - 0}{6.2s} = 15.7m/s^2

F(friction) = F(net) - F(applied)

= F(net) - 14000N

F(net) = ma
= 800kg x 15.7m/s^2
= 12560N

F(friction) = 12560N - 14000N = -1440N

The solution says 10900N.

Where did I do wrong?
 
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