When will a load of hay be overturned?
It will be overturned whenever the line from the centre of gravity to the earth falls outside of the wheels, as is shown in [Fig. 36].
Fig. 36.
Why should lamps have large bottoms?
Lamps should have large bottoms so that the line of gravity may not fall outside of the bottom.
Where must the line of gravity in a body always fall?
It must always fall within the base of that body, or the body will be overturned.
How must a leaning tower be built so as not to fall?
It must be built so that the line of gravity will fall within its base.