Answer :
Final answer:
The time required to bring a 1200 kg car moving at 10 m/s to rest when a braking force of 3000 N is applied is calculated to be 4 seconds using Newton's second law of motion and the equation of motion for constant acceleration.
Explanation:
To calculate the time required to bring the car to rest, we need to determine the car's deceleration using Newton's second law of motion (Force = mass × acceleration). The deceleration a is the braking force F divided by the car's mass m:
a = F / m. Substituting the given values, we get a = 3000 N / 1200 kg = 2.5 m/s^2.
Next, using the equation v = u + at, where v is the final velocity (0 m/s since the car is coming to rest), u is the initial velocity (10 m/s), and t is the time, we can solve for the time:
0 = 10 m/s + (-2.5 m/s^2) × t
This simplifies to t = -10 m/s / (-2.5 m/s^2) = 4 seconds. Therefore, the correct answer is A) 4 seconds.
