Answer:
The angular speed of the system increases.
The moment of inertia of the system decreases.
Explanation:
As we know that the girl is going towards the center of the circle so here the moment of inertia of the girl is given as

here we know that
r = position of the girl from the center of the disc
now we know that the girl is moving towards the center so its distance will continuously decreasing
So the moment of inertia of the girl will decrease
Now we know that that with respect to the center of the disc there is no torque on the disc + girl system
So here we can use angular momentum conservation
So we have

since moment of inertia is decreasing for the system
so angular speed will increase
Answer:
The visible light frequency is 400 THz to 700 THz, approximately. A THz is a Terahertz, which is a unit of frequency equal to one trillion Hertz.
The heavier it is the more frictions it creates sliding on the floor. this make more kinetic energy.
Remember Newton's second law: F=ma
to get the force in newtons, mass should be in kg and acceleration in m/s^2
conveniently, we don't need to convert units
we just need to multiply the two to get the force
65* 0.3 = 19.5 kg m/s^2 or N
if significant digit is an issue, the least number if sig figs is 1 so the answer would be 20 N
To calculate for the average speed, we simply divide the total distance covered by the time it takes to travel that distance. In this case, we simply divide 7.5 km with 45 min. Therefore, the skier's average speed is 0.1667 km/min. Hope this helps.