Answer:
Explanation:
The condition that the sphere completes the loop is that it doesn't fall off at the top. In order to do that, the sphere has to have enough velocity to beat the centripetal acceleration.
The forces acting on the sphere at the top of the loop:
1- Weight of the sphere to the downwards direction.
2- The normal force to the downwards direction.
So Newton's Second Law gives the following equation
At the minimum velocity, which corresponds to minimum height 'h', the normal force is equal to zero. That means, if the sphere moves any less than the minimum velocity, its weight will be greater than the centripetal force, hence it will fall off.
Therefore,
Now, we can use the conservation of energy to find the minimum height.
The book has potential energy and the bike has kinetic.
kinetic energy is energy possessed when a object is in motion. The bike is moving. Therefore, it has kinetic energy. The book isn't moving. Hopefully that helped
Answer:
Multiple answers:
1. Power output P=17.59W
2.Intensity 160m I=17.6W/
3. dB = 77.3
4. f=178.5 Hz
Explanation:
First one comes from the expression
where<em> I </em>is the intensity, <em>P </em>is the power and <em>r </em>is the radio of the spherical wave, or in this case, the distance <em>x</em>. I solved for the Power by multiplying Intensity with the area (4
Second one is done with:
Solving for Intensity 2, the result mentioned.
The third is simply computed with
And finally the last one is done with doppler effect, taking into account the speed of the air as in 10ºC 337m/s.
Where <em>Finitial</em> is the frequency emitted and <em>s</em> is the speed of the sound. The wind blowing in positive is, in principle, going away of the observer.
In atoms, electrons surround the nucleus in specific energy levels.
Answer: Option B
<u>Explanation:
</u>
Atom, actually considered as the tiny part that is ever present in this universe. Many theories and experiments were conducted, for studying what was present inside of an atom, and many theories came into light.
And finally, Bohr-Sommerfeld Theory stated the final conclusion, that the positive charge is at the centre of the nucleus, and all the electrons revolve in their specific energy levels. If an atom wants to move to lower energy state, it should emit energy, whereas for going to higher state, it should gain energy.
The rotational speed of the two children is the same.
In fact, it is defined as
where
is the angle covered in the time
. As it can be seen, this quantity does not depend on the distance from the centre, so the rotational speed is 4.0 revolutions per minute for both children.