What force is needed to accelerate a car

[smarties]

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?

 

[danago]

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.

 

[baba89]

I would like to clarify that the equations used in the attempt at a solution are correct. However, there is a slight error in the final calculation for force. The correct calculation should be F = 1200kg x 9 m/s^2 = 10,800 N. This is because the unit for acceleration is m/s^2, not just m/s.

To answer the question, the force needed to accelerate a 1200kg vehicle from rest to 108 km/hr in 100m is 10,800 Newtons. This force is necessary to overcome the inertia of the car and provide the acceleration required. It is important to note that this is the minimum force required, and factors such as friction and air resistance may also affect the actual force needed in real-world situations.