If a car accelerates uniformly from rest to a speed of 72 km/h in 10 seconds, wh
Practice Questions
Q1
If a car accelerates uniformly from rest to a speed of 72 km/h in 10 seconds, what is its acceleration? (2023)
2 m/s²
3 m/s²
4 m/s²
5 m/s²
Questions & Step-by-Step Solutions
If a car accelerates uniformly from rest to a speed of 72 km/h in 10 seconds, what is its acceleration? (2023)
Step 1: Understand that acceleration is the change in speed over time.
Step 2: Identify the initial speed of the car. Since it starts from rest, the initial speed is 0 m/s.
Step 3: Convert the final speed from km/h to m/s. 72 km/h is equal to 20 m/s (since 1 km/h = 1/3.6 m/s).
Step 4: Calculate the change in speed. The final speed is 20 m/s and the initial speed is 0 m/s, so the change in speed is 20 m/s - 0 m/s = 20 m/s.
Step 5: Identify the time over which this change occurs. The time given is 10 seconds.
Step 6: Use the formula for acceleration: Acceleration = (Final Speed - Initial Speed) / Time.
Step 7: Plug in the values: Acceleration = (20 m/s - 0 m/s) / 10 s.
Step 8: Calculate the acceleration: 20 m/s / 10 s = 2 m/s².
Acceleration – Acceleration is the rate of change of velocity of an object. It can be calculated using the formula: Acceleration = (Final Speed - Initial Speed) / Time.
Unit Conversion – Understanding the need to convert speed from km/h to m/s is crucial for accurate calculations in physics.
