A car is coasting backwards down a hill at -5.0 m/s when the driver gets the engine started. After 4 seconds, the car is moving uphill at a velocity of +3 m/s. What is the car’s average acceleration?
a = (Vf-Vo)/t = (3-(-5)) / 4 = 2 m/s^2.
To find the car's average acceleration, we need to use the equation:
Acceleration (a) = Change in velocity (Δv) / Time (Δt)
First, let's find the change in velocity (Δv):
Δv = Final velocity - Initial velocity
The final velocity is 3 m/s (moving uphill) and the initial velocity is -5.0 m/s (coasting backwards).
So, Δv = 3 m/s - (-5.0 m/s)
= 3 m/s + 5.0 m/s
= 8.0 m/s
Now, let's find the time duration (Δt) which is given as 4 seconds.
Substitute these values into the formula to find the average acceleration:
Acceleration (a) = Δv / Δt
= 8.0 m/s / 4 s
= 2.0 m/s^2
Therefore, the car's average acceleration is 2.0 m/s^2.
To find the car's average acceleration, you need to calculate the change in velocity and divide it by the time taken.
Step 1: Find the change in velocity
The car initially has a velocity of -5.0 m/s when coasting backwards and after 4 seconds, it has a velocity of +3 m/s when moving uphill. To find the change in velocity, subtract the initial velocity from the final velocity:
Change in velocity = Final velocity - Initial velocity
Change in velocity = 3 m/s - (-5.0 m/s)
Change in velocity = 3 m/s + 5.0 m/s
Change in velocity = 8.0 m/s
Step 2: Find the time taken
The time taken for the car to change its velocity is given as 4 seconds.
Step 3: Calculate average acceleration
Average acceleration = Change in velocity / Time taken
Average acceleration = 8.0 m/s / 4 s
Average acceleration = 2.0 m/s²
Therefore, the car's average acceleration is 2.0 m/s².