# Problem: The mass of a sports car is 1 200 kg. The shape of the body is such that the aerodynamic drag coefficient is 0.250 and the frontal area is 2.20 m2. Ignoring all other sources of friction, calculate the initial acceleration the car has if it has been traveling at 100 km/h and is now shifted into neutral and allowed to coast.

###### FREE Expert Solution

This problem requires us to determine the acceleration given the forces acting on the object.

This is Dynamics with resistive Forces: Forces-Drag type of problem.

The steps involved are simple and straight forward!

1. Determine the forces acting on the object
2. Set up Newton's second law equation, F = ma
3. Solve the target!

In step 1, our problem involves Frictional drag force. We'll use the following equation:

Frictional drag force: $\overline{){\mathbit{f}}{\mathbf{=}}\frac{\mathbf{1}}{\mathbf{2}}{\mathbf{\left(}}{{\mathbf{\rho v}}}^{{\mathbf{2}}}{\mathbf{A}}{{\mathbf{C}}}_{{\mathbf{d}}}{\mathbf{\right)}}}$

Where f is frictional drag force, ρ is the density of air, v is the speed of the car, A is the frontal area, and Cd is the drag coefficient

100% (11 ratings)
###### Problem Details

The mass of a sports car is 1 200 kg. The shape of the body is such that the aerodynamic drag coefficient is 0.250 and the frontal area is 2.20 m2. Ignoring all other sources of friction, calculate the initial acceleration the car has if it has been traveling at 100 km/h and is now shifted into neutral and allowed to coast.