* 248. Fig. 3.1 shows a firefighter of total weight 840 N in equilibrium at the top of a
ladder that is pivoted at point P.
I
C
ladder
112m
5.0m
P.
Fig. 3.1
The ladder leans towards a burning building at an angle such that the centre of gravity C
of the firefighter is 12 m above and 5.0 m to the right of P. The firefighter holds a hose
that directs a high-speed jet of water horizontally into a burning building.
(a) i) Calculate the moment M of the firefighter's weight about P.
moment =
[2]