A cheetah can run 113 km/h in short busts. How far can a cheetah run in 0.25 hours (15 minutes)?
1 answer:
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Answer:
<em>A) the moment of inertia of the system decreases and the angular speed increases. </em>
Explanation:
The complete question is
A merry-go-round spins freely when Diego moves quickly to the center along a radius of the merry-go-round. As he does this, It is true to say that
A) the moment of inertia of the system decreases and the angular speed increases.
B) the moment of inertia of the system decreases and the angular speed decreases.
C) the moment of inertia of the system decreases and the angular speed remains the same.
D) the moment of inertia of the system increases and the angular speed increases.
E) the moment of inertia of the system increases and the angular speed decreases
In angular momentum conservation, the initial angular momentum of the system is conserved, and is equal to the final angular momentum of the system. The equation of this angular momentum conservation is given as
....1
where and
are the initial and final moment of inertia respectively.
and and
are the initial and final angular speed respectively.
Also, we know that the moment of inertia of a rotating body is given as
....2
where is the mass of the rotating body,
and is the radius of the rotating body from its center.
We can see from equation 2 that decreasing the radius of rotation of the body will decrease the moment of inertia of the body.
From equation 1, we see that in order for the angular momentum to be conserved, the decrease from to
will cause the angular speed of the system to increase from
to
.
From this we can clearly see that reducing the radius of rotation will decrease the moment of inertia, and increase the angular speed.
Answer: 20.21 kg
Explanation:
The mass hanging from the pulley is pulling the cart. The force by which cart is being pulled is equal to weight of the hanging mass.
⇒F=0.200 kg ×9.8 m/s²=1.96 N
Since there is no other force acting on the cart and there is no friction, so this force will pull the cart.
The Cart covers 1.12 m distance in 4.8 s.
From the equation of motion,
s = u t + 0.5 × a t²
We will find the acceleration of the cart,
Distance covered, s = 1.12 m
Initial velocity, u = 0 ( staring from rest)
Time taken, t = 4.8 s
⇒1.12 m = 0 + 0.5 × a × (4.8 s)²
⇒a = 0.097 m/s²
Now the force which causes this acceleration is:
F = ma
where m is the mass of the cart and a is the acceleration of the cart
⇒1.96 N = m×0.097 m/s²
⇒m = 20.21 kg
Hence, the mass of the cart is 20.21 kg.
Which of the following are characteristics of noble gases?
✅
- An inert gas is one that does not undergo chemical reactions. The noble gases have complete outer shells, so they have no tendency to lose, gain, or share electrons. This is why they are said to be inert.
✅
- Noble gases are the least reactive of all elements. This is because they already have the desired eight total 's' and 'p' electrons in their outermost (highest) energy level.