Final answer:
The resultant velocity is 4.8 m/s. It will take 83.3 seconds for the boat to reach the shore, and it will reach the opposite shore at a distance downstream of 291.6 m.
Step-by-step explanation:
To find the resultant velocity, we can use the Pythagorean theorem because the boat's velocity and the current's velocity form a right triangle. The magnitude of the resultant velocity is given by:
Vresultant = sqrt((Vboat)^2 + (Vcurrent)^2)
Substituting the values, Vboat = 3.3 m/s and Vcurrent = 3.5 m/s, we get:
Vresultant = sqrt((3.3 m/s)^2 + (3.5 m/s)^2) = 4.8 m/s
To find the time it takes for the boat to reach shore, we can use the formula:
Time = Distance / Velocity
Substituting the values, Distance = 0.4 km and Velocity = 4.8 m/s, we need to convert the distance to meters:
Distance = 0.4 km imes 1000 m/km = 400 m
Time = 400 m / 4.8 m/s = 83.3 s
The boat will reach the opposite shore at a distance downstream equal to the velocity of the river multiplied by the time it takes to cross the river:
Distance downstream = Vcurrent imes Time = 3.5 m/s imes 83.3 s = 291.6 m