Question

14. A space craft flying in a straight course with a
velocity of 75 km s-1 fires its rocket motors for
6.0 s. At the end of this time, its speed is
120 km s-1 in the same direction. Find : (i) the space
craft's average acceleration while the motors were
firing, (ii) the distance travelled by the space craft
in the first 10 s after the rocket motors were started,
the motors having been in action for only 6-0 s.


Plz tell me the method fast.... ill mark it as brainliest....​

Answer 1

Answer:

well, this a question about spacecraft, not rocket science, let me try,

i)

initial speed(u)=75km/s

final speed(v)=120km/s

time=6seconds

so acceleration=(v-u)/t

=(120-75)/6=45/6=7.5m/s²

ii)

s=ut+1/2at²

first, we will find it for 6 seconds while the motor was started

s1=75x6+7.5x18

s1=585m

now distance travelled in the next 4 seconds

using the same formula:

s2=120x4+1/2x16

s2=488m

here we have taken u=120 m/s t=4s and a=1 because, in space, everything moves at constant speed unless an external force is applied.