What force is needed to accelerate a car

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SUMMARY

The discussion centers on calculating the force required to accelerate a 1200 kg vehicle from rest to 108 km/h over a distance of 100 meters. The correct approach involves using the equations for acceleration and force, specifically: Force = Mass x Acceleration. The user initially calculated the final velocity as 30 m/s and derived a time of 3.33 seconds, leading to an acceleration of 9 m/s². However, the calculation of time must account for the changing velocity, indicating a misunderstanding of the kinematic equations.

PREREQUISITES
  • Understanding of Newton's Second Law of Motion
  • Familiarity with kinematic equations
  • Basic knowledge of unit conversions (km/h to m/s)
  • Concept of acceleration and its calculation
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  • Study the derivation and application of kinematic equations in non-uniform acceleration
  • Learn about the relationship between force, mass, and acceleration in detail
  • Explore practical examples of force calculations in automotive physics
  • Investigate the implications of changing velocity on time and distance calculations
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Students studying physics, automotive engineers, and anyone interested in understanding the principles of motion and force calculations in vehicles.

smarties
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Homework Statement



What force is needed to make a 1200kg vehicle accelerate from rest to 108km/hr in 100m

Homework Equations



aceleration = Velocity/time

Force = Mass x Acceleration

Time = Distance/Velocity

The Attempt at a Solution



M = 1200kg

D = 100m

V = 108 km/hr / 3.6 = 30 m/s

t = 100m/30 m/s = 3.33sec

a = 30 m/s / 3.33sec = 9 m/s

F = 1200 x 9 m/s = 10800kg

Now do I need to convert the kg to Newtons? by multiplying by gravity 9.8m/s I am a bit confused about that?
 
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Be careful with how you calculated the time of the trip.

You used t=s/v, but that equation is for the case when the acceleration is zero.

The velocity of the car isn't 30m/s for the whole trip, only at the end.
 

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