Question

a small ball ia dropped from a balloon moving vertically above at a speed of 10m/s when the balloon is at height 15m above the ground. Neglect air friction and take g=10m/s^2. which of the following is not true?
(a) the ball reaches the ground in 3 sec.
(b) the bal covers a distance of 25m.
(c) the magnitude of average velocity of the ball is 8.33 m/s
(d) the ball moves up with a speed of 10m/s qt an instant where it ia dropped from the balloon

Answer 1

Answer:

Explanation:

Step by step explanation:

Total Displacement of the ball = 15m

from the first equation of motion:v = u −gt0 = 10 − 10tt = 1snow,h' = ut −12gt2h' = 10×1 − 12×10×12h' = 5mnow,Let time taken to fall h'+15 meters it t'then,h'+15 = ut' + 12gt'220 = 0×t' + 12×10×t'2t'2 = 4t' = 2snow,total time to fall on the ground = 3stotal distance covered = h' + h' + 15 = 25maverage velocity = total displacement total time =153 = 5 m/s

Thus magnitude of the average velocity cannot be 8.33 m/s

hence,

Option (c) is the correct answer