Question

please solve this question​

Answer 1

Case 1

d=600km

s=s(let)

t=t(let)

Then ,

d=s×t

→600=st-------(1)

→s=600/t-------(2)

Case 2

d=600km

s=s-200

t=t+30/60

t=t+1/2

d=s×t

600=(s-200)(t+1/2)--------(3)

From (1) &(3)

St=(s-200)(t+1/2)

st=st+1/2s-200t-100

100=(s-400t)/2

s-400t=200------(4)

Substitute value of s from equation (2) into equation (4)

600/t-400t=200

600-400t^2=200t

400t^2+200t-600=0

Dividing each term by 100

4t^2+2t-6=0

Dividing each term by 2

2t^2+t-3=0

2t^2+3t-2t-3=0

2t(t+3)-2(t+3)=0

(2t-2)(t+3)=0

t+3=0

→t=-3

Duration of flight cannot be negative according to classical physics

So,

2t-2=0

→t=1

So duration of flight is 1 hour