To calculate the magnitude of the frictional force applied by the road to stop a car, we need to use Newton's second law of motion, which states that the net force acting on an object is equal to the product of its mass and acceleration. In this case, the acceleration represents the deceleration of the car.
The equation is:
F = m * a
where F is the force, m is the mass of the car, and a is the acceleration.
Assuming that the car is initially moving and comes to a complete stop, the acceleration can be determined using the following kinematic equation:
v² = u² + 2as
where v is the final velocity (0 m/s in this case), u is the initial velocity, a is the acceleration, and s is the distance covered.
Since the car stops, the final velocity is 0 m/s. Therefore, the equation becomes:
0 = u² + 2as
Solving for a:
a = -u² / (2s)
Now we can substitute this value of acceleration into the equation for force:
F = m * (-u² / (2s))
Make sure to use consistent units throughout the calculation.
