How may the distance a body falls in a given time be found?
It may be found by multiplying the number of seconds it is in falling, by the same number, and this product by sixteen feet. Thus, when it is three seconds in falling, multiply three by three, and this product by sixteen feet, which gives one hundred and forty-four feet, the distance it falls in three seconds.
What familiar example have we of the force of falling bodies?
We have an example in the large hail-stones which fall to the earth in summer-time, breaking the glass in our windows and doing much injury to the crops.
Centre of Gravity.
What is the centre of gravity in a body?
The centre of gravity in a body, is the point on which the body may be balanced, as is shown in [Fig. 30].
Fig. 30.
Where is the centre of gravity in a circle?