Question

10. A balloon is ascending at the rate of 4.9m/s. A packet is dropped from the balloon when situated at a height of 245m. How long does it take the packet to reach the ground?
(a) 6.6s (b) 10.6s (c) 5.6s (d) 7.6 s

Answer 1

AnSwEr:–

$\longrightarrow\sf{7.6\:s\: option (d)}$

SteP By SteP ExplainaTion:–

• initial velocity (u)= 4.9 m/s

• height of balloon (h1) = 245 m

• final height (h2) = 0

• acceleration (a)=-9.8 m/s²

•Let the time taken be 't'

•Now, using second equation of motion

s=ut+0.5at²

→ h2-h1=ut+0.5at²

→0-245=4.9t+0.5(-9.8)t²

→ -245=4.9t+4.9t²

→4.9t²-4.9t-245=0

solving equation we get

→ t= 7.6 sec (approx)

Answer 2

Answer:

AnSwEr:–

\longrightarrow\sf{7.6\:s\: option (d)}⟶7.6soption(d)

SteP By SteP ExplainaTion:–

• initial velocity (u)= 4.9 m/s

• height of balloon (h1) = 245 m

• final height (h2) = 0

• acceleration (a)=-9.8 m/s²

•Let the time taken be 't'

•Now, using second equation of motion

s=ut+0.5at²

→ h2-h1=ut+0.5at²

→0-245=4.9t+0.5(-9.8)t²

→ -245=4.9t+4.9t²

→4.9t²-4.9t-245=0

solving equation we get

→ t= 7.6 sec (approx)

Explanation:

hope its help you

=====----ayan