Answer:

Explanation:
Given:
angular speed of rotation of friction-less platform, 
moment of inertia with extended weight, 
moment of inertia with contracted weight, 
<u>Now we use the law of conservation of angular momentum:</u>



The angular speed becomes faster as the mass is contracted radially near to the axis of rotation.
Answer:

3257806.62409 m/s
Explanation:
G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²
M = Mass of Sun = 
r = Radius of Star = 20 km
u = Initial velocity = 0
v = Final velocity
s = Displacement = 16 m
a = Acceleration
Gravitational acceleration is given by

The gravitational acceleration at the surface of such a star is 

The velocity of the object would be 3257806.62409 m/s
Answer:
29.7 m/s fast, velocity is 29.7 m/s
Explanation:
Applying,
v² = u²+2gs...................... Equation 1
Where v = final velocity, u = initial velocity, g = acceleration due to gravity, s = distance.
Given: u = 0 m/s (dropped from height), s = 45 m
Constant: g = 9.8 m/s²
Substitute these values into equation 1
v² = 0²+2×9.8×45
v² = 882
v = √(882)
v = 29.7 m/s.
Hence the stone will be moving 29.7 m/s fast and the velocity is also 29.7 m/s
In transversal wave particles do not oscillate along the line of the wave propagation but oscillate up and down about their mean position as the wave travels.thus transverse wave is the one in which individual particles of the medium move about their mean position in a direction perpendicular to the direction of wave propprgation.
In longitutional waves the individual particles of the medium move in the direction parallel to the direction of the propprgation of the disturbance. The particles do not move from one place to another but the simply oscillate back and forth about their position of the rest.
HOPE IT HELPS.