a) 6.25 rad/s
The law of conservation of angular momentum states that the angular momentum must be conserved.
The angular momentum is given by:
where
I is the moment of inertia
is the angular speed
Since the angular momentum must be conserved, we can write
where we have
is the initial moment of inertia
is the initial angular speed
is the final moment of inertia
is the final angular speed
Solving for , we find
b) 28.1 J and 35.2 J
The rotational kinetic energy is given by
where
I is the moment of inertia
is the angular speed
Applying the formula, we have:
- Initial kinetic energy:
- Final kinetic energy:
Answer:
The second snowball hits the ground with a kinetic energy of 100 Joules
Explanation:
Given that,
From the edge of a roof you throw a snowball downward that strikes the ground with 100 J of kinetic energy. It is a case of conservation of energy.
At the highest point,
At lowest point,
From above two equation, we get :
Kinetic energy, K = 100 J
So, the second snowball hits the ground with a kinetic energy of 100 Joules. So, the correct option is (A).
Answer: a) 0.12m; b) 1,6 s; c) 0.625 1/s
Explanation: The simple harmonic movement can be described by a sin or cosine function in time.
This can be in the form:
X(t)= A Sin/Cos (wt+φ) where φ is initial phase o position at t=0
w the angular frequency are related to the frequency (f) as 2Pif
and f=1/T period of oscillating
Answer:
Stars are very massive stellar objects, which means that they have a very intense force of gravity. This is the first of the forces entering this "war".
In addition to that, due to the force of gravity that drives the star to contract, the process known as fusion occurs (the union of atoms of one element that results in another element, hydrogen fuses in stars to produce helium). The fusion created in the high temperatures of the center of the star generates an enormous amount of energy (which causes the stars to shine) and a force going outward of the star counteracting gravity, this is the second force in the "war" .
In a stable star these two forces (gravity going inward and the pressure created by the fusion going outward ) are in balance, preventing the star from exploding or collapsing. But eventually the star exhausts its "fuel" (hydrogen atoms) to produce fusion within it (although stars also fuse helium and other heavier elements, but once the hydrogen is finished the star is near its end), which decreases the force outward from the star, making the force that wins this battle to be the force of gravity.
When the force of gravity wins, the star collapses on itself and from here, depending on the star's mass, several things can happen, such as the star becoming a white dwarf, a supernova, even a black hole.
