Question

Plzz solve fast class 11th

Answer 1

initial velocity u of stone= 20

Displacement in 5 sec by balloon = 20×5 = 100

s= ut + 1/2 at^2

-100= 20 t - 5 t^2

t^2 - 4 t -20= 0

t = 4+-√16+80)/2 = 4+-√96)/2

= 4+ √96)/2 ( neglect - ve)

= 4+4√6)/2 = 2( 1+√6) = 2(3.4) = 6.8

2) v= u + at

=- 20 +5(6.8) = 34-20= 14

3) distance = 2× 100= 200