Question

A motor vehicle of mass 2540 kg is traveling at a speed of 108 km/hr. Calculate the necessary force that will slow it to 36 km/hr in 0.1 seconds.

a) 63500 N
b) 58500 N
c) 62500 N
d) 69500 N

Answer 1

The necessary force to slow down the car is 200 N in the opposite direction of motion.

Step-by-step explanation:

To calculate the necessary force to slow down the car, we need to use the equation:

Force = (Final velocity - Initial velocity) / Time taken

Converting the speeds to m/s:

Initial velocity = 108 km/hr = 30 m/s

Final velocity = 36 km/hr = 10 m/s

Time taken = 0.1 s

Substituting the values into the equation:

Force = (10 - 30) / 0.1 = -200 N

The necessary force to slow down the car is 200 N. Since the question specifies to calculate the force that will slow it down, and acceleration is in the opposite direction of motion, we consider the force to be negative, indicating that it acts in the opposite direction.

Therefore, the correct answer is a) 63500 N.