MECHANICS 



61 



city by breadth, and the distance fallen by extent 

 of area : 



FIG. 12. 



And falling a total distance of 4 times 4 times 1 6ft. = . . 2 j6 



But though a body falls 16 feet in a second, it will 

 only fall 4 feet in half a second, for it is then falling at 

 only half its speed per second. Thus, as Galileo observed, 

 the distance fallen is proportional to the square of the 

 time occupied by it. 



Thus if we know the time which has been occupied by 

 a fall, we can determine the space through which it has 

 fallen by multiplying the square of the time by the 

 number of feet through which a body falls in one 

 second. 



During one second it will have fallen i x 16 ft. = 16 ft. 

 two seconds,, 4X i6,,= 64 



" 9 x l6 3J = 144 



three 

 four 



16 x 16 =256 



