Answer:19.5 J
Explanation:
Given
mass of block=3 kg
angular frequency=20 rad/sec
spring constant 
we know total energy remain conserved
Where 
=kinetic energy
=potential Energy
When mass reaches amplitude its velocity becomes zero
there is only potential energy which is equal to Total energy
Since angular speed is persistent, v/r is constant.
Where:
v is tangential speed;
and
r is distance from
axis.
Then equate v/r in both cases to get v in the second case.
Hence, speed = 2.2 x 2.1 / 1.4 meters
= 3.3 meters / seconds
Alternative solution would be:
w = 2.2 / 1.4 = 1.57
v = rw = 2.1 x 1.57 = 3.3 meters / seconds
The first positively essential requirement is that
you absolutely have to know what 'a' and 'b' are.
I have no clue, so this is as far as I can go.
Answer:
72.75 kg m^2
Explanation:
initial angular velocity, ω = 35 rpm
final angular velocity, ω' = 19 rpm
mass of child, m = 15.5 kg
distance from the centre, d = 1.55 m
Let the moment of inertia of the merry go round is I.
Use the concept of conservation of angular momentum
I ω = I' ω'
where I' be the moment of inertia of merry go round and child
I x 35 = ( I + md^2) ω'
I x 35 = ( I + 25.5 x 1.55 x 1.55) x 19
35 I = 19 I + 1164
16 I = 1164
I = 72.75 kg m^2
Thus, the moment of inertia of the merry go round is 72.75 kg m^2.
It expands due to heat and makes it easier to open the jar.<span />
