The Work Required to Stop a Car

To calculate the work required to stop a car, we need to consider the mass of the car, its initial velocity, and the final velocity. In this case, the car has a mass of 1500 kg and is moving at a velocity of 60 km/h.

Step 1: Convert the velocity to meters per second

Firstly, we need to convert the velocity from kilometers per hour to meters per second, as the SI unit for velocity is meters per second. We can use the conversion factor of 1 km/h = 0.2778 m/s.

Given velocity: 60 km/h
Converted velocity: 60 km/h × 0.2778 m/s = 16.67 m/s

So, the car is moving at a velocity of 16.67 m/s.

Step 2: Calculate the change in velocity

Since the car needs to come to a complete stop, the final velocity is 0 m/s. We need to determine the change in velocity.

Change in velocity = Final velocity - Initial velocity
Change in velocity = 0 m/s - 16.67 m/s = -16.67 m/s

The negative sign indicates that the car is decelerating or slowing down.

Step 3: Calculate the work required

The work required to stop the car can be calculated using the formula:

Work = Force × Distance

The force required to stop the car is equal to the product of its mass and the change in velocity. The distance is not given, but since we are only calculating the work required, we can assume that the distance is negligible.

Force = Mass × Change in velocity
Force = 1500 kg × (-16.67 m/s) = -25005 N

The negative sign indicates that the force is acting in the opposite direction of the car's motion.

Finally, we can calculate the work:

Work = Force × Distance
Work = -25005 N × 0 m = 0 J

Therefore, the work required to stop the car is 0 Joules. This means that no work is required since the distance is negligible and there is no force acting in the direction of motion.