Answer:
155.5 rev/min
Explanation:
First, we will calculate the initial moment of inertia I_o. We will consider the ice skater as a rod rotating around its axis. Then, we calculate the final moment of inertia I_f. In this occasion we consider the arms as a rod of length L that is horizontally positioned, L so that the length of an arm is L/2. We will call M_1 the mass that remains close to the rotation axis (90 percent) and M_2 the mass located at the arms (10 percent). Finally, we write the equation for the conservation of angular momentum and we solve for ω_f.
I_o=MR^2/2
=(45)(0.15)^2/2
=0.5 kgm^2
M_1=(0.9)(45)
=40.5 kg
M_2=(0.1)(45)
=4.5 kg
I_f=M_1*R^2/2+M_2*L^2/12
=1.1 kg m^2
I_f*ω_f=I_o*ω_o
ω_f = I_o*ω_o/ I_f
=155.5 rev/min
Force is ALWAYS measured in Newtons (N)
<span>According
to the special theory of relativity, all laws of nature
are the same in
reference frames that move at constant speeds.
That means that there's no test or measurement you can do to
detect whether you're moving at a constant speed</span> or how fast.
And THAT means that there's no such thing as "who's REALLY
moving" and "who's REALLY at rest". There's no such thing as
"real" motion, only motion relative to something else.
The initial velocity of the potato is 54.41 m/s.
The given parameters:
- <em>Mass of the potato, m = 0.34 kg</em>
- <em>Mass of the cart, m = 5.0 kg </em>
- <em>Velocity of the recoil, u₂ = 3.7 m/s</em>
<em />
The initial velocity of the potato is calculated by applying the principle of conservation of energy as follows;
![m_1u_1 = m_2 u_2\\\\u_1 = \frac{m_2 u_2}{m_1} \\\\u_1 = \frac{5 \times 3.7}{0.34} \\\\u_1 = 54.41 \ m/s](https://tex.z-dn.net/?f=m_1u_1%20%3D%20m_2%20u_2%5C%5C%5C%5Cu_1%20%3D%20%5Cfrac%7Bm_2%20u_2%7D%7Bm_1%7D%20%5C%5C%5C%5Cu_1%20%3D%20%5Cfrac%7B5%20%5Ctimes%203.7%7D%7B0.34%7D%20%5C%5C%5C%5Cu_1%20%3D%2054.41%20%5C%20m%2Fs)
Thus, the initial velocity of the potato is 54.41 m/s.
Learn more about conservation of linear momentum here: brainly.com/question/7538238