Final answer:
The braking force needed to stop a car of mass 1200 kg decelerating at 30 m/s² is calculated using Newton's second law of motion, and the answer is 36,000 N.
Step-by-step explanation:
To determine the braking force needed to stop a car of mass 1200 kg decelerating at 30 m/s², we apply Newton's second law of motion, which states that force equals mass times acceleration (F = ma). By multiplying the car's mass (1200 kg) by the deceleration (30 m/s²), we get:
F = 1200 kg × 30 m/s² = 36,000 N.
Therefore, the braking force needed to stop the car is 36,000 N, which corresponds to option A).