A boat travels due east at a speed 40ms-1s across a river flow due south at 30ms-1s. What is the resultant speed of the boat?
Answer Details
To find the resultant speed of the boat, we need to use the Pythagorean theorem which states that in a right-angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides.
In this case, the boat's velocity and the river's velocity are perpendicular to each other, so we can form a right-angled triangle.
The speed of the boat is given as 40 ms^-1 due east, and the speed of the river's flow is 30 ms^-1 due south.
Using Pythagoras theorem, we have:
Resultant speed = √(40^2 + 30^2) = √(1600 + 900) = √2500
Resultant speed = 50 ms^-1
Therefore, the correct option is 50.0ms^-1.