A motorcycle is moving at a constant speed of 4 km/h. How long does it take the motorcycle to travel a distance of 10 km
2 answers:
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The maximum current in an ac circuit is related to the rms current by:
where
is the rms current and 
is the maximum current.
If we re-arrange the formula and we use
, we can find the value of the maximum current:
where
If we re-arrange the formula and we use
Answer:
200 J
Explanation:
In this problem, I assume there is no air resistance, so the system is isolated (=no external forces).
For an isolated system, the total mechanical energy is constant, and it is given by:
where
KE is the kinetic energy
PE is the potential energy
The kinetic energy is the energy due to the motion of the object, while the potential energy is the energy due to the position of the object relative to the ground.
At the beginning, when the boulder is raised above the ground, its height above the ground is maximum, while its speed is zero; it means that all its mechanical energy is just potential energy, and it is:
As the boulder falls down, its altitude decreases, so its potential energy decreases, while the speed increases, and the kinetic energy increases. Therefore, potential energy is converted into kinetic energy.
Eventually, just before the boulder hits the ground, the height of the object is zero, and the speed is maximum; this means that all the energy has now converted into kinetic energy, and we have
Therefore, the kinetic energy just before hitting the ground is 200 J.
Answer:
Explanation:
Frequency of each electromagnetic wave is same thus we can interfere them along X axis in Phase diagram.
In phase diagram indicate each wave as vector with amplitude as length and phase difference as angle. (shown in attachment)
Now take component of E2 and E3 amplitude along X direction.
Net amplitude of all E in X direction = + cos(45)[
+
]
⇒
Final resultant have no change in frequency
So , resultant is
