A balloon of volume F, contains a gas whose density is to that of the air at the earth's surface as 1:15. If the envelope of the balloon be of weight w but of negligible volume, find the acceleration with which it will begin to ascend.

\[\left( \frac{14Vg\sigma +w}{Vg\sigma -w} \right)\times g\]

\[\left( \frac{7Vg\sigma -w}{Vg\sigma +w} \right)\times g\]

\[\left( \frac{2Vg\sigma -w}{Vg\sigma +w} \right)\times g\]

\[\left( \frac{14Vg\sigma -w}{Vg\sigma +w} \right)\times g\]

A balloon of volume F, contains a gas whose density is to that of the

1.	A balloon of volume F, contains a gas whose density is to that of the air at the earth's surface as 1:15. If the envelope of the balloon be of weight w but of negligible volume, find the acceleration with which it will begin to ascend.
A.	\[\left( \frac{7Vg\sigma -w}{Vg\sigma +w} \right)\times g\]
B.	\[\left( \frac{2Vg\sigma -w}{Vg\sigma +w} \right)\times g\]
C.	\[\left( \frac{14Vg\sigma -w}{Vg\sigma +w} \right)\times g\]
D.	\[\left( \frac{14Vg\sigma +w}{Vg\sigma -w} \right)\times g\]
Answer» D. \[\left( \frac{14Vg\sigma +w}{Vg\sigma -w} \right)\times g\]