Final answer:
To calculate the average acceleration of a racehorse that starts from rest and reaches a velocity of 15.0 m/s due west in 1.80 seconds, use the formula a = ∆v / ∆t, which results in an average acceleration of -8.33 m/s².
Step-by-step explanation:
To determine the average acceleration of a racehorse leaving the gate, you can use the formula for average acceleration:
a = ∆v / ∆t
Where a is the average acceleration, ∆v is the change in velocity, and ∆t is the change in time.
The change in velocity (∆v) for the horse is its final velocity minus its initial velocity. Since the horse starts from rest, its initial velocity is 0 m/s, and the final velocity is given as -15.0 m/s. Thus, the change in velocity is:
∆v = vf - vi = -15.0 m/s - 0 m/s = -15.0 m/s
The change in time (∆t) during which this change in velocity occurs is 1.80 seconds.
Now substituting these values into the formula for average acceleration, we get:
a = ∆v / ∆t = -15.0 m/s / 1.80 s = -8.33 m/s².
The negative sign indicates that the acceleration is directed westward (in the opposite direction to the positive coordinate direction which is typically eastward).