A car accelerates at a constant rate from zero to 23.3 m/s in 10 seconds and then slows to 15 m/s in 5 seconds. What is its average acceleration to the nearest tenth of a m/s^2 during the 15 seconds?
Since the final velocity after 15 seconds is 15 m/s, the average acceleration is (15m/s)/(15s) = 1 m/s^2
It's exactly like saying a car moved 23.3m in 10 s, then went back to 15m from its starting point in 5 more seconds. What is the average speed? 1m/s
@ Steve. The answer to the question is 0.7m/s^2
To find the average acceleration, we need to calculate the total change in velocity and divide it by the total time taken.
Step 1: Calculate the change in velocity
The first part of the motion involves an increase in velocity from 0 m/s to 23.3 m/s, while the second part involves a decrease in velocity from 23.3 m/s to 15 m/s.
Change in velocity for the first part: 23.3 m/s - 0 m/s = 23.3 m/s
Change in velocity for the second part: 15 m/s - 23.3 m/s = -8.3 m/s (negative because it's a decrease)
Step 2: Calculate the total time taken
The car accelerates for 10 seconds and then slows down for 5 seconds, giving us a total time of 10 + 5 = 15 seconds.
Step 3: Calculate the average acceleration
Average acceleration = total change in velocity / total time taken
Average acceleration = (23.3 m/s + (-8.3 m/s)) / 15 s = 15 m/s / 15 s ≈ 1.0 m/s^2 (rounded to the nearest tenth)
Therefore, the average acceleration of the car during the 15 seconds is approximately 1.0 m/s^2.