Question

A lift in which a man is standing, is moving upwards with a speed of 10 m s−1
. The man drops a coin from a height of 4.9 metre and if g = 9.8 m s−2
, then the coin reaches the floor of the lift after a time

Answer 1

$\huge\underline{\underline{\bf \orange{Question-}}}$

A lift in which a man is standing, is moving upwards with a speed of ${\sf 10m/s}$. The man drops a coin from a height of 4.9 metre and if g = 9.8m/s² then the coin reaches the floor of the lift after a time

$\huge\underline{\underline{\bf \orange{Solution-}}}$

$\large\underline{\underline{\sf Given:}}$

• Initial Velocity of lift (u) = 0m/s
• Velocity of lift (v) = 10m/s
• Man drop a coin from height (h)=4.9m
• g = 9.8 m/s²

$\large\underline{\underline{\sf To\:Find:}}$

• Coin reaches the floor of the lift after a time

❏$\large{\boxed{\bf \blue{h=ut+\dfrac{1}{2}gt^2} }}$

$\implies{\sf 4.9 = 0 × t + \dfrac{1}{2}×9.8×t^2 }$

$\implies{\sf t^2=\dfrac{4.9×2}{9.8} }$

$\implies{\sf t^2=\dfrac{9.8}{9.8} }$

$\implies{\bf \red{ time(t )= 1\:sec}}$

$\huge\underline{\underline{\bf \orange{Answer-}}}$

Coin reaches the floor of the lift after a time ${\bf\red{1s}}$.