<span>The answer is 15 centimeters. The waves with the
smallest wavelengths (also highest
frequency) have the least capacity to diffract around objects hence have a
shadowing effect, behind the object, especially if the wavelength is small
compared to the object. This is also the reason why high-frequency electromagnetic waves do not have a good reach in mountainous
regions. </span>
Answer:
v1 = v2
Explanation:
Given:
- The missing figure is (attached).
- The Magnetic Field B1 > B2
Find:
How does the speed v1 of the electron in region 1 compare with the speed v2 in region 2?
Solution:
- From Lorentz Law we know that the Force that acts on the charge particle is the cross product of Magnetic Field Vector ( B1 or B2 ) and the velocity vector (v1 or v1).
- From the attached figure related to this problem we see that the electron velocity or direction of motion is always parallel to the magnetic field B1&B2.
- The law of cross product for parallel vector is 0. Hence, the Lorentz force acting on the electron is also zero.
- Zero Force means no work is done on the particle by the magnetic field, thus, the change in kinetic energy also zero for conservation of energy to hold.
- The initial and final kinetic energies of the electron is same. Hence, we can conclude that v1 = v2.
“The mechanical energy is conserved" in the given system is true out of all given options.
Answer: Option 2
<u>Explanation:
</u>
According to law of conservation of energy, the energy will neither be created nor be destroyed, irrespective of the type of energy. As in the present case, the ball is bowled and it is travelling to ground, so the mechanical energy is working in this case. Thus the mechanical energy will be conserved. Even it can be shown as follows.
As the 2 kg ball is travelling with a speed of 7 m/s, the kinetic energy exhibited by the ball while falling to ground will be
Thus, applying given values, we get,
Similarly, as the ball is 2.5 m above ground, the potential energy will also be exhibited by the ball at that position. So the potential energy will be
Thus,
Thus as the magnitude of kinetic energy is equal to the magnitude of potential energy exhibited by the ball with varying direction, the net energy will be zero. This is because the kinetic energy will be acting in opposite direction to the potential energy exhibited by the ball. Hence as the net energy is zero, the mechanical energy is conserved.
Because it is shorter and easier to write out such as .100000000000000 is easier to write in Scientific notation