Question

8. A ball dropped from a balloon at rest clears a
tower 81 m high during the last quarter second
of its journey. Find the height of the balloon
and the velocity of the body when it reaches
the ground.
(Ans. 2684.2 m, 324.38 m/s)
​

Answer 1

Answer:

Hope this helps you

Explanation:

To find velocity of ball at the height of 81m

h=ut+0.5gt×t

81=u/4 +0.5×9.8×1/16

81=u/4+4.9/16

324=u+1.225

u=324–1.225=322.775 m per sec

To find at what speed the ball touched the ground.

V×V -U×U=2×9.8×81

V*V=1587.6+104167=105754.6

V=325.2 m/sec

Height of balloon

V×V-U×U=2×9.8×h

105754/2× 9.8= 5395.6 meters