A certain type of rocket sled is used to measure the effects of extreme deceleration. The sled reaches a velocity of +320 km/h, then comes to a complete stop in 0.18 s. What is the average acceleration that takes place in this time interval?
320 km/hr * 1000m/km * 1hr/3600s = 88.889 m/s
so a = -88.889/0.18 = -493.83 m/s^2
Why put a negative sign
To find the average acceleration, we can use the formula:
Average acceleration = (change in velocity) / (time interval)
First, let's convert the velocity from km/h to m/s.
Given:
Initial velocity (u) = 0 km/h (since the sled comes to a complete stop)
Final velocity (v) = 320 km/h
Time interval (t) = 0.18 s
Converting velocities from km/h to m/s:
Initial velocity (u) = 0 km/h = 0 m/s
Final velocity (v) = 320 km/h = (320 * 1000) m/3600 s = 88.9 m/s
Now, we can calculate the change in velocity:
Change in velocity = Final velocity - Initial velocity
= 88.9 m/s - 0 m/s
= 88.9 m/s
Finally, we can calculate the average acceleration using the formula:
Average acceleration = (change in velocity) / (time interval)
Average acceleration = 88.9 m/s / 0.18 s
= 494.4 m/s^2
Therefore, the average acceleration that takes place in this time interval is 494.4 m/s^2.
To calculate the average acceleration, we can use the formula:
Acceleration = (Final Velocity - Initial Velocity) / Time
In this case, the initial velocity is +320 km/h (since we have a positive velocity), the final velocity is 0 km/h (as the sled comes to a complete stop), and the time interval is 0.18 seconds.
However, we need to convert the velocities from km/h to m/s because the unit of acceleration is meters per second squared (m/s^2). To convert km/h to m/s, we divide the velocity by 3.6 (since 1 km/h = 1/3.6 m/s).
Let's plug the values into the formula:
Initial Velocity = 320 km/h = 320/3.6 m/s = 88.9 m/s
Final Velocity = 0 km/h = 0/3.6 m/s = 0 m/s
Time = 0.18 s
Acceleration = (0 m/s - 88.9 m/s) / 0.18 s = -88.9 m/s / 0.18 s ≈ -494.4 m/s^2
So, the average acceleration that takes place in this time interval is approximately -494.4 m/s^2. Notice that the negative sign indicates deceleration, as the rocket sled is slowing down.