284 
Mr Sears, On the Longitudinal Impact 
Static tests of Aluminium Specimen. 
Length 18". 
Mean diam. ... - 509". 
Weight -.3562 lbs. 
Density 168-1 lbs. per cub. ft. 
Extensometer test. 
Calibration of Instrument... 1 div. = 1/966". 
Length under test 8". 
Load (lbs.) 
Beading 
Difference 
Load (lbs.) 
Beading 
Difference 
Mean 
0 
3-98 
0 
0 
4-00 
0 
0 
200 
4-70 
■72 
200 
4-77 
•77 
•745 
400 
5-49 
1-51 
400 
5-50 
1-50 
1-505 
600 
6-26 
2-28 
600 
6-29 
2-29 
2-285 
800 
7-02 
3-04 
800 
7-05 
3-05 
3-045 
1000 
7-80 
3-82 
1000 
7-83 
3-83 
3-825 
1200 
8-59 
4-61 
1200 
8-60 
4-60 
4-605 
1000 
7-83 
3-85 
1000 
7-89 
3-89 
3-87 
800 
7-08 
3-10 
800 
7-10 
3-10 
3-10 ! 
600 
6-30 
2-32 
600 
6-35 
2-35 
2-335 
400 
5-54 
1-56 
400 
5-59 
1-59 
1-575 
200 
4-79 
•81 
200 
4-80 
•80 
•805 
0 
4-00 
•02 
0 
404 
•04 
•03 
Plotting, we see this gives 4'64 divs. for 1200 lbs. when 
loading and 4 60 when unloading. Taking the mean of these. 
4'62, we get : — 
F _ Sx 966 x 1200 x 4 
4‘62 x 7 r x (-509) 2 
= 9,868,000 lbs. per sq. in. 
000 x 32-18 x 144 
168-1 
= 16,490 ft. per sec. 
Hence 
v = 
