Question

A sailboat is traveling to the right when a gust of wind causes the boat to accelerate leftward at 2.5\,\dfrac{\text m}{\text s^2}2.5

s
2

m
​
2, point, 5, start fraction, start text, m, end text, divided by, start text, s, end text, squared, end fraction for 4\,\text s4s4, start text, s, end text. After the wind stops, the sailboat is traveling to the left with a velocity of 3.0\,\dfrac{\text m}{\text s}3.0
s
m
​
3, point, 0, start fraction, start text, m, end text, divided by, start text, s, end text, end fraction.

Answer 1

Initial speed of the sail boat is 7 m/s

Step-by-step explanation:

Acceleration of the sail boat is towards left opposite to the direction of initial motion given as

a = - 2.5 m/s/s

after t = 4 s then final velocity of sailboat is also towards left and it is given as

`v_f = -3 m/s`

now by kinematics we have

`v_f - v_i = at`

so we have

`- 3 - v_i = (-2.5) 4`

`v_i = 10 - 3`

`v_i = 7 m/s`