Resistance of the Air to Falling Spheres. 



731 



(1) Air Resistance and Velocity for a Sphere of 3*70 cm. 

 diam. — The table gives the results . R = resistance in dynes ; 

 S = area of diametric plane of the sphere in cm. 2 ; V = 

 velocitv in cm./sec. ; K=the so-called "constant" in the 

 usually assumed equation ; R = KSV 2 . (R was the weight 

 of the sphere, and V the corresponding terminal velocity.) 



s. 



cm 2 . 



V. 



cm./sec. 



E. 



dynes. 



K. 



gius./crn. 3 



1076 



851 



1937 



2-495 Xl0- 4 



1076 



962 



2555 



2-563 „ 



10-76 



1044 



3014 



2-565 „ 



10-76 



1162 



3816 



2-624 „ 



10-76 



1319 



4974 



2-660 „ 



It is evident that in this case K is not a constant. If R 

 is plotted against V 2 , the result is a straight line (A in the 

 figure) which does not pass through the axis, but is repre- 

 sented by the equation : 



R = 2-77xl0- 4 SV 2 + 216. 



DTNU 



5*IO r 



w 



^ 3H0 3 



^ I MO 3 



(C(//?V£ B) (DMAf£T£/?f — - 



10 ao 30- 40 



60 cm 1 



A air - h esistanl 'E*(mdc/rr) £ 



FOR SPHERE 3-70 



bf\lR-RtSIST/\NC£&(DlMETERY 

 foAv£LOC/rr 10-30 \ m / S £ C 



cmD/METER 



14* K) 3 



12x10" 



10*10 



6x|Q 3 I 



£*I0 5 4*I0 5 6M0 5 8*I0 S JOxlO 5 l^io s i4*i0 5 I6*i0 5 ""/sec* 

 (CURVE P\){V£LOCJTyf - 



I? 



2-10 OD 



The distance of fall available did not allow of the attainment 



of higher limiting velocities. 



3B2 



