Question

a spaceship is moving in space with a velocity of 50km/s its engine fires for 10,such that its velocity increases to n60km/s calculate the total distance travelled by the spaceship in 1/2 min from the time of firing its engine

Answer 1

distance travelled in the first 10 seconds, =  avg velocity * time
     s1 = (50+60)/2 km/s * 10 sec  = 550 km

distance travelled inthe next 20 sec =  60 km/s * 20 s = 1, 200 km

so total distance in 30 sec. = 1, 750 km

Answer 2

Explanation:

u = 50kms = ×1000ms¹ 50000ms¹

ms¹t =10

ms¹t =10v =60kms =×1000ms¹ , 60000ms¹

CASE I

acceleration for first 10s

v= u + at

6000 =50000 +10a

10a = 60000 - 50000=10000

10a = 10000

a= 10000÷10 = 1000 m/s²

s= ut +½ at²

s = 50000×10 +½ 1000×10²

s = 550km

CASE II

spaceship moves with unifrom velocity 60km/s for next 20s

Distance covered = unifrom velocity ×time

= 60× 20

1200

total distance travelled = 1200 +550 =1750km