Answer:
Explanation:
a )
In space due to weightlessness both astronaut and her oxygen tank will float .
when she throws the tank away from spacecraft , she will have a velocity in opposite direction ie towards the spacecraft . This happens due to conservation of momentum . She creates a momentum away so that she can get a momentum towards the spaceship.
So
m₁ v₁ = m₂v₂
12 x 8 = ( 87 - 12 ) x v₂
v₂ = 1.28 m /s
Time allowed = 2 x 60
= 120 s
So maximum distance upto which she can remain away from spacecraft
= 120 x 1.28
= 153 m .
b )
The Newton's law which explains the theory behind it is "third law of motion" . This law gives law of conservation of momentum .
Answer: The torque required is 0.0471 N m.
Explanation:
Mass of the disc = 200 g = 0.2 kg (1 kg =1000 g)
Radius of the disc =
= 10 cm = 0.1 m(1 m = 100 cm)
Angular acceleration = 

Moment of inertia = 

The torque required is 0.0471 N m.
Answer:
The speed, magnitude of the velocity, magnitude of the angular velocity, magnitude of the centripetal acceleration, magnitude of the net force and direction of the angular velocity are constant.
Explanation:
In uniform circular motion we have a centripetal acceleration of constant magnitude but changing direction (since it points to the center of the circle from the object). The same goes for the net (centripetal) force since F=ma. This makes the magnitude of the velocity (speed) constant but its direction changes, although keeping spinning in the same direction, which makes its angular velocity constant in both magnitude and direction.
Answer:
They are in free-fall motion.
Explanation:
The Earth orbiting astronauts are falling at an acceleration that is the same or greater than the acceleration due to gravity i.e., 9.81 m/s². If you are continuously falling at this rate then you will feel weightless.
This same effect is felt while going down in an elevator. When you down in an elevator you feel that you are lighter and feel that something is pushing you up. Earth-orbiting astronauts feel the same effect but the accelration is greater hence they feel weightless.
Answer:

Explanation:
Given:
- mass of the body stretching the spring,

- extension in spring,

- velocity of oscillation,

- initial displacement position of equilibrium,

<u>According to given:</u>



<u>we know frequency:</u>



Now, for position of mass in oscillation:


at 
∴
∵ at 
