Final answer:
The drag force on a car moving at 65 mi/hr can be calculated using the equation for drag force. By comparing the drag forces at 65 mi/hr and 45 mi/hr, you can find how many times bigger the drag force is at the higher velocity.
Step-by-step explanation:
To calculate the drag force on a car, you can use the equation:
Drag Force = 0.5 * Drag Coefficient * Air Density * Area * Velocity^2
Since we are comparing two cars moving at different velocities, we can use the equation to find the drag forces at each velocity and then compare them.
Let's assume that the drag coefficient, air density, and drag area are the same for both cars. The only difference is the velocity.
At 65 mi/hr (around 104.6 km/h), the drag force on the car would be:
Drag Force1 = 0.5 * Drag Coefficient * Air Density * Area * (104.6 km/h)^2
At 45 mi/hr (around 72.4 km/h), the drag force on the car would be:
Drag Force2 = 0.5 * Drag Coefficient * Air Density * Area * (72.4 km/h)^2
To find how many times bigger the drag force is at 65 mi/hr compared to 45 mi/hr, you can divide Drag Force1 by Drag Force2:
Ratio = Drag Force1 / Drag Force2
This will give you the factor by which the drag force at 65 mi/hr is bigger than at 45 mi/hr.