Question

please answer fast.....

Answer 1

Average acceleration is 2okm/sec

Answer 2

aircraft initial velocity = 75 km/sec
after 6 sec velcity of aircraft = 120 km/s

use kinematics equation , becoz motion is linear .

V = U + at

here V = 120 km/s
U = 75 km/s
t = 6 sec

120 = 75 + a× 6

45 /6 = a

a = 7.5 km/s² = 7500 m/s²

hence average acceleration = 7500 m/s²

###

motors action only for 6sec
it means aircraft accelerated only for 6 sec. after that it's velocity is constant .e.g = 120km/s

now
distance travelled by aircraft in 10 sec = distance travelled in 6sec + distance travelled in next 4 sec.

distance within first 6 sec = S

S = Ut + 1/2at²
= 75 × 6 + 1/2 × 15/2 × 36
= 450 + 135
= 585 km


distance travelled next 4sec = S"
S" = Vt'
= 120 × 4 = 480 km

now,

total distance travelled by aircraft = S + S" = 585 + 480 = 1065 km