Coefficiant of friction between rubber tires and wet pavement is 0.50. brakes are applied to a 750kg car, intitally travelling at 30m/s and the car skids to a stop. What is the size and direction of the acceleration of the car.
What is 0.8?
force= mu*mg=.5*750*0.8 N
direction has to be opposite to the direction of travel, to stop it.
To determine the size and direction of the acceleration of the car, we can use Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. The equation for the second law is:
F = m * a
Where F represents the net force, m represents the mass, and a represents the acceleration.
In this case, the net force is provided by the friction between the tires and the wet pavement. The frictional force can be calculated using the equation:
f_friction = μ * N
Where μ represents the coefficient of friction and N represents the normal force acting on the car. The normal force can be found by multiplying the mass of the car by the acceleration due to gravity (9.8 m/s^2).
Given:
μ = 0.50
m = 750 kg
v = 30 m/s (initial velocity)
First, let's calculate the normal force:
N = m * g = 750 kg * 9.8 m/s^2 = 7350 N
Next, calculate the frictional force:
f_friction = μ * N = 0.50 * 7350 N = 3675 N
Since the car is skidding to a stop, the direction of the net force is opposite to the initial motion. Therefore, the net force can be considered negative.
Now, to calculate the acceleration, rearrange Newton's second law equation:
F = m * a => a = F / m
Substituting the values we have:
a = (-f_friction) / m = (-3675 N) / 750 kg
Calculating the acceleration:
a = -4.9 m/s^2
The negative sign indicates that the acceleration is in the opposite direction of the initial motion. Therefore, the size of the acceleration is 4.9 m/s^2, and the direction of the acceleration is opposite to the initial motion of the car.