Question

An aeroplane moving horizontally with a speed of $720km/h$ drops a food packet, while flying at a height of $396.9m$. The time taken by a food packet to reach the ground and its horizontal range is (Take $g=9.8m/{\sec }^2)$.

• A. $3sec$ and $2000m$
• B. $5sec$ and $500m$
• C. $8sec$ and $1500m$
• D. $9sec$ and $1800m$

Answer 1

The correct option is D $9sec$ and $1800m$

We know that

As the packet simply gets dropped, it's initial vertical velocity u = 0

Time taken for the packet to reach ground is

T =√(2H/g) = √(2*396.9/9.8) = √81 = 9s

Horizontally the packet travels at the speed of aeroplane,

V = 720kmph = 720*(5/18) = 200m/s

Range R = V*T = 200*9 = 1800m