A car of mass 1000 kg is moving with a velocity of 20 m/s. What is the net force
Practice Questions
Q1
A car of mass 1000 kg is moving with a velocity of 20 m/s. What is the net force required to bring it to rest in 5 seconds?
4000 N
2000 N
1000 N
500 N
Questions & Step-by-Step Solutions
A car of mass 1000 kg is moving with a velocity of 20 m/s. What is the net force required to bring it to rest in 5 seconds?
Correct Answer: 4000 N
Step 1: Identify the mass of the car, which is 1000 kg.
Step 2: Identify the initial velocity of the car, which is 20 m/s.
Step 3: Identify the final velocity of the car, which is 0 m/s (since we want to bring it to rest).
Step 4: Identify the time over which the car needs to stop, which is 5 seconds.
Step 5: Calculate the deceleration (a) using the formula: a = (final velocity - initial velocity) / time.
Step 6: Substitute the values into the formula: a = (0 m/s - 20 m/s) / 5 s.
Step 7: Simplify the calculation: a = -20 m/s / 5 s = -4 m/s².
Step 8: Since we need the magnitude of the force, take the absolute value of deceleration, which is 4 m/s².
Step 9: Use Newton's second law to find the net force (F) using the formula: F = mass * acceleration.
Step 10: Substitute the values: F = 1000 kg * 4 m/s².
Step 11: Calculate the force: F = 4000 N.
Newton's Second Law of Motion – This law states that the force acting on an object is equal to the mass of that object multiplied by its acceleration (F = ma).
Deceleration – Deceleration is the rate at which an object slows down, which can be calculated as the change in velocity over time.
Kinematics – Kinematics involves the study of motion without considering the forces that cause it, focusing on parameters like velocity, acceleration, and time.