Frictional force of car homework

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SUMMARY

The discussion revolves around calculating the frictional force acting on a dragster that accelerates from rest to 350 km/h in 6.2 seconds. The dragster has a mass of 800 kg and generates a driving force of 14,000 N. The calculated net force is 12,560 N, leading to a frictional force of -1,440 N, which indicates an error in the calculations. The correct frictional force, as per the solution provided, is 10,900 N, highlighting the importance of accurately applying Newton's second law and understanding the relationship between net force and applied force.

PREREQUISITES
  • Understanding of Newton's second law of motion
  • Basic knowledge of force calculations
  • Familiarity with unit conversions (e.g., km/h to m/s)
  • Ability to perform algebraic manipulations
NEXT STEPS
  • Review Newton's second law of motion and its applications
  • Practice converting units, specifically speed from km/h to m/s
  • Explore the concept of net force and its components in physics
  • Investigate common mistakes in force calculations and how to avoid them
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Students studying physics, particularly those focusing on mechanics and force calculations, as well as educators looking for examples of common errors in problem-solving.

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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

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

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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