00:01
In this problem, we have been given that a 24 pound force that's applied as shown here.
00:07
So let's take this point as b where this force is applied.
00:11
And as a result of which the system rotates about this point b.
00:16
And a torque is produced and we are required to determine the magnitude of that torque produced about this point b.
00:23
So we know the expression of the torque that's r cross f.
00:27
Or basically we can see it's the product of force times, it's perpendicular distance from the point about which it rotates.
00:36
So here this is the perpendicular distance, and let's take this distance as d, which is what we need to determine.
00:43
And before that, we observed that, as this is four feet and this is also four feet, applying pythagoras rule, the length of this side p .b, that will be root of four square plus four square, and this comes out to be 4 root 2.
01:00
So this will be 4 root 2.
01:03
And also we observed that this angle, it is 45 degrees, because both these sides are equal in this triangle, p -o -b.
01:12
So even this angle is 45 -degree, and by geometry, this angle is 45 -degree.
01:17
And thus we conclude that this total angle, this is 45 plus 30, that's 75 degrees...