A paratrooper jumps from an aeroplane and opens a parachute after 2 s of free fall and starts decelerating with 3 $m / s ²$ . At 10 m height from ground, while descending with the help of parachute, the speed of paratrooper is 5 m/s. The initial height of the airplane is __________ m.
$(g = 10 m / s^{2})$ [2026]

Question

Smart Achievers · Accepted Answer

(4)

$A to B$

$x_{1} = \frac{1}{2} \times 10 \times 2^{2} = 20 m$

$V = 0 + 10 \times 2$

$B to C$

$5^{2} = 20^{2} - 2 (3) x_{2}$

$x_{2} = \frac{375}{6}$

$x_{2} = 62.5$

$C to D$

$x_{3} = 10 m$

$H = x_{1} + x_{2} + x_{3} = 92.5$

Solution

1 20

2 62.5

3 82.5

4 92.5

Ans.
(4)

$A to B$

$x_{1} = \frac{1}{2} \times 10 \times 2^{2} = 20 m$

$V = 0 + 10 \times 2$

$B to C$

$5^{2} = 20^{2} - 2 (3) x_{2}$

$x_{2} = \frac{375}{6}$

$x_{2} = 62.5$

$C to D$

$x_{3} = 10 m$

$H = x_{1} + x_{2} + x_{3} = 92.5$

Want Us to Email you About Special Offers & Updates?