Answer:
The angular speed of the record is 3.36 rad/s.
Explanation:
Given that,
Mass of record= 0.10 kg
Radius = 0.10 m
Angular speed = 4.7 rad/s
Moment of inertia 
Mass of putty = 0.020 kg
We need to calculate the angular speed
Using law of conservation of momentum



Put the value into the formula


Hence, The angular speed of the record is 3.36 rad/s.
Attached a diagram of the scheme described in the problem ..
To solve the problem we need to know the relationship between kinetic and normal force, so

Where
coefficient of kinetic
Normal force
We perform the sum of forces as well,
(2)

For Normal Force in Y,
(3)
The force in X,
(4)
Replacing in (4)




In this way, it does not matter which object is chosen.
Answer:
thermal
Explanation:
when an object's atoms move it causes friction, when friction happens, it heats ups causing thermal energy
Answer:
Lilly's speed is two times John's speed.
Explanation:
m = Mass
a = Acceleration
t = Time taken
u = Initial velocity
v = Final velocity
The force they apply on each other will be equal




Hence, Lilly's speed is two times John's speed.