5. A balloon is ascending at the rate of 4.9m/s. A pocket is dropped from the balloon when situated at a height of 245m. How long does it take the packet to reach the ground? What is its final velocity?

initial velocity, u = 4.9 m/s

final velocity = v m/s

initial height, h₁ = 245 m

final height, h₂ = 0

a = - 9.8 m/s²

time taken = t seconds

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 it, we get t = 7.59s

v = u + at = 4.9 - 9.8*7.59 = 4.9 - 74.38 = - 69.48 m/s

velocity is 69.48 m/s downward