Question

A man on the bank of the river pulls a boat on water with the rope that makes 30 degrees, with the bank. He exerts a force of 60lbs. What is the useful component of this force?why is it called useful?

Answer 1

Solution

Diagram is shown as

Here is useful component

Is x- axis

$F_x=F\cos \theta \\F_x=60\cos 30^°\\ F_x=60\times\frac{\sqrt{3}}{2}$

$F_x=51.96lb$

Change in Newton

$F_x=203.77N$