1000 kg car moving at 10 m/s brakes to a stop in 5 s. The average braking force is ? n
To find the average braking force, we can use Newton's second law of motion, which states that the force acting on an object is equal to its mass multiplied by its acceleration: F = m * a.
In this case, since the car is braking to a stop, its acceleration can be found using the equation of motion: v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time taken.
Given:
Initial velocity, u = 10 m/s
Final velocity, v = 0 m/s
Time taken, t = 5 s
Mass of the car, m = 1000 kg
Using the equation v = u + at and solving for acceleration:
0 = 10 + a * 5
-10 = 5a
a = -10/5
a = -2 m/s² (negative sign indicates deceleration)
Now that we have the acceleration, we can calculate the average braking force using Newton's second law. F = m * a:
F = 1000 kg * (-2 m/s²)
F = -2000 N
The average braking force exerted on the car is 2000 Newtons (N), which acts in the opposite direction of the car's motion.