Question

8. A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are

used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space

colonization, planetary exploration, and transportation of humans and cargo.

(i) An astronaut undergoing training is rotated in a seat at the end of a horizontal rotating arm of length 5m. If

he can withstand accelerations up to 9g, then what is the maximum number of revolutions per second

permissible? You may use suitable approximations.

a. 13.5rps

b. 1.35rps

c. 0.675rps

d. 6.75rps

(ii) If a spacecraft of mass M moving with velocity v in free space explodes and breaks into two pieces. After

explosion a mass m of the spacecraft is left stationary. The velocity of the other part will be

a. mv/(M-m)

b. (M+m)/mv

c. Mv/(M-m)

d. Mv/m

(iii) If the space craft undergoes UCM, about which point on the plane of the circle, will the angular momentum

of the particle remain conserved?

a. Centre of the circle

b. On the circumference of the circle

c. Inside the circle

d. Outside the circle

(iv) Astronauts can feel like crying, or they could get something in their eye that causes the tear ducts to produce

liquid, but the tears just stick to the surface of the eyeball because of

a. Lack of gravity

b. Lack of surface tension.

c. Lack of air pressure

d. None of the above

(v) No force is required for

a. An object moving in straight line with constant velocity

b. An object moving in circular motion

c. An object moving with constant acceleration​

Answer 1

Answer:

d

Exdplanation:

d