<u>Answer :</u>
(a) d = 0.25 m
(b) d = 0.5 m
<u>Explanation :</u>
It is given that,
Frequency of sound waves, f = 686 Hz
Speed of sound wave at
is, v = 343 m/s
(1) Perfectly destructive interference occurs when the path difference is half integral multiple of wavelength i.e.
........(1)
Velocity of sound wave is given by :




Hence, when the speakers are in phase the smallest distance between the speakers for which the interference of the sound waves is perfectly destructive is 0.25 m.
(2) For constructive interference, the path difference is integral multiple of wavelengths i.e.
( n = integers )
Let n = 1
So, 


Hence, the smallest distance between the speakers for which the interference of the sound waves is maximum constructive is 0.5 m.
Answer:
The normal force will be lower than the gravitational force acting on the car. Therefore the answer is N < mg, which is <em>option B</em>.
Explanation:
Over a round hill, the centripetal force acting toward the the radius of the hill supports the gravitational force (mg) of the car. This notion can be expressed mathematically as follows:
At the top of a round hill

At the foot of a round hill

Answer:
Explanation:
During an energy transfer, the collision loss for an electron can be determined by using the formula:

However; from the total stopping power & power loss of the electron;

where;
Z = atomic no. for lead = 82
E = 1.9 MeV
∴
radiational energy loss = collisional energy loss 
= 0.19475
b)
Normally, the traditional lead shielding in its pure shape contains high brittleness. However, the functionality of this carbon group chemical element is useful for protection because it has an excessive density.
Initially, the conventional lead protection however reduces the mild clarity at the same moment as plexiglass is useful for light transmittance and readability.
Moreover, the traditional lead with its high density and thickness reduces observation features, in the meantime, the plexiglass is a whole lot higher than the stated.
Finally, plexiglass contains a high dimensional balance with an excessive dielectric constant.
<span>it fairly is going to attain a speed of 24 m/s in a 2d, yet between t = 0 and t = a million, it fairly is not any longer vacationing at that speed, yet at slower speeds. it fairly is 12 meters. ?D = [ ( a?T^2 + 2?Tv_i ) ] / 2 the place: ?D = displacement a = acceleration ?T = elapsed time v_i = preliminary speed ?D = [ ( 24m/s^2 • 1s • 1s + 2 • 1s • 0m/s ) ] / 2 ?D = 24 / 2 ?D = 12m</span>
Answer:
A. They have the same atomic numbers.
Explanation:
Elements are defined based on the atomic number, which is the number of protons in the nucleus: this means that atoms of the same element have always the same number of protons in their nuclei (and so, always the same atomic number).
The other choices are wrong because:
B. They have the same average atomic masses. --> this is false for isotopes, which are atoms of the same element having a different number of neutrons. Since the atomic mass is calculated from the sum of the masses of protons and neutrons in the nucleus, two isotopes of the same element have different atomic mass
C. They have the same number of electron shells. --> this can be false when an atom of an element loses/gains an electron, becoming an ion: in that case, the number of electron shells can change, since the number of electrons has changed.
D. They have the same number of electrons in their outermost shells. --> this is also false in case one of the atoms is an ion, since the number of electrons is different.