A car company states that their car can
accelerate from rest to 70km/h in 7 seconds. What is the cars average acceleration?
Convert the speed to meters per second, and divide the result by 7 seconds.
70 km/h = 70,000 m/3600 s = 17.44 m/s
17.77/7 = ___ m/s^2
To find the car's average acceleration, we can use the formula:
Average Acceleration = Change in Velocity / Time Taken
Here, the change in velocity is the difference between the final velocity and the initial velocity. The car starts from rest, so the initial velocity is 0 km/h, and the final velocity is 70 km/h. The time taken is given as 7 seconds.
Therefore, the change in velocity = final velocity - initial velocity = 70 km/h - 0 km/h = 70 km/h.
Now we can plug these values into the formula:
Average Acceleration = 70 km/h / 7 sec
To simplify the units, we can convert km/h to m/s since acceleration is typically measured in meters per second squared (m/s^2).
1 km/h = 1000 m / 60 min / 60 sec = 0.2778 m/s (approximately)
Average Acceleration = (70 km/h) * (0.2778 m/s/km) / 7 sec
After canceling units, we get:
Average Acceleration = 2.778 m/s / 7 sec
Now we can calculate the average acceleration:
Average Acceleration = 0.397 m/s^2 (approximately)
Therefore, the car's average acceleration is approximately 0.397 m/s^2.