Answer:

Explanation:
Given that,
Angular speed of a skater, 
The moment of inertia of the skater, I = 0.6 kg-m²
We need to find the angular momentum of the skater. The formula for the angular momentum of the skater is given by :

Substitute all the values,

So, its angular momentum is equal to
.
question 2 answer is ALL OF THE ABOVE
question 3 answer is WARM AND MOIST.
Answer:
Part a)

Part b)

Part c)

Explanation:
Part a)
As we know that the friction force on two boxes is given as



Now we know by Newton's II law

so we have




Part b)
For block B we know that net force on it will push it forward with same acceleration so we have




Part c)
If Alex push from other side then also the acceleration will be same
So for box B we can say that Net force is given as




Answer: 0.169 (3 s.f.)
Explanation:
Force = 76 N
Spring constant = 450 N/m
Extension/displacement = x
Hooke's law states that: F = kx
Therefore, 76 = 450 X x
76/450 = x
0.169 (3 s.f.) = x