Answer:
h> 2R
Explanation:
For this exercise let's use the conservation of energy relations
starting point. Before releasing the ball
Em₀ = U = m g h
Final point. In the highest part of the loop
Em_f = K + U = ½ m v² + ½ I w² + m g (2R)
where R is the radius of the curl, we are considering the ball as a point body.
I = m R²
v = w R
we substitute
Em_f = ½ m v² + ½ m R² (v/R) ² + 2 m g R
em_f = m v² + 2 m g R
Energy is conserved
Emo = Em_f
mgh = m v² + 2m g R
h = v² / g + 2R
The lowest velocity that the ball can have at the top of the loop is v> 0
h> 2R
I think it’s A.) it explains why the universe is made up of matter
Answer:
They would land at the same time
Explanation:
They would land at the same exact time.
As weird, impossible and unbelievable as it appears. When in a vacuum, every weight, body and material when released from the same height would land on the ground at the same time. This also means that like in the question, a feather and a ball would land at the same time. And just for illustrations as well, a feather and a car would land at the same time as well.
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