The drag coefficient = 0.354

The mass of car = 1200 kg
rolling resistance = 180 N
Air density = 1.181 kg m^-3
Frontal area = 1.88 m^2

What is the deceleration at a speed of 82 km h^-1 when the car is taken up to high speed and then allowed to coast down on a level road.

Deceleration = (net backwards force) / mass

82 km/h = 22.78 m/s

Air drag force = (1/2)*(density)*(frontal area)*V^2
= (0.5)*(1.181)*(1.88)*(22.78)^2
= 576 N
Rolling resistance = 180 N

deceleration = (576+180)/1200 = 0.63 m/s^2

To calculate the deceleration of the car, we need to use the equation:

deceleration = (force of drag + force of rolling resistance) / mass of the car

First, let's calculate the force of drag. The drag force can be calculated using the equation:

force of drag = (1/2) * drag coefficient * air density * frontal area * velocity^2

where the velocity is in m/s. We need to convert the speed from km/h to m/s by dividing it by 3.6:

velocity = 82 km/h = (82 * 1000) / 3600 = 22.78 m/s

Now, we can calculate the force of drag:

force of drag = (1/2) * 0.354 * 1.181 * 1.88 * (22.78)^2

Next, let's calculate the force of rolling resistance, which is given as 180 N.

Now, substitute the values into the equation for deceleration:

deceleration = (force of drag + force of rolling resistance) / mass of the car

deceleration = (force of drag + 180) / 1200

Calculate the numerator:

numerator = force of drag + 180

Finally, substitute the values into the equation for deceleration:

deceleration = numerator / 1200

Now, calculate the deceleration and round it to the appropriate number of significant figures.