A sailboat is traveling to the right when a gust of wind causes the boat to accelerate leftward at 2.5m/s^2 . After the wind stops, the sailboat is traveling to the left with a velocity of 3.0m/s. Assuming the acceleration from the wind is constant, what was the initial velocity of the sailboat before the gust of wind? Answer using a coordinate system where rightward is positive.

+7.0 m/s

Explanation:

Let's take rightward as a positive direction.

So in this problem we have:

a = -2.5 m/s^2 acceleration due to the wind (negative because it is leftward)

t = 4 s time interval

v = -3.0 m/s is the final velocity (negative because it is leftward)

We can use the following equation:

v = u + at

Where u is the initial velocity

We want to find u, so if we rearrange the equation we find:

u = v - at = (-3m/s) - (-2.5m/s^2) (4s) = +7.0m/s

and the positive sign means the initial direction was rightward.