<em>A statement that is true for ALL of the examples of electromagnetic waves is that;</em>
A) They all move at the same speed in a vacuum
<u>The reason for qualifying 'in vacuum' is because EM waves of different frequencies often propagate at different speeds through material. Generally speaking, we say that light travels in waves, and all electromagnetic radiation travels at the same speed which is about 3.0 * 108 meters per second through a vacuum.</u>
Answer:
Cruising at 35,000 feet in an airliner, straight toward the east,
at 500 miles per hour
Explanation:
Answer:
e) indicated that the speed of light is the same in all inertial reference frames.
Explanation:
In 18th century, many scientists believed that the light just like air and water needs a medium to travel. They called this medium <em>aether</em>. They believed that even the space is not empty and filled with aether.
Michelson and Morley tried to prove the presence and speed of this aether through an interference experiment in 1887. They made an interferometer in which light was emitted at various angles with respect to the supposed aether. Both along the flow and against the flow to see the difference in the speed of light. But they did not find no major difference and thus it became the first proof to disprove the theory of aether.
It thus proved that the speed of light remains same in all inertial frames.
Also, it became a base for the special theory of relativity by Einstein.
Answer:
(B) tightly packed protons and neutrons
Explanation:
- Nucleus of any atom is the dense central part of any atom.
- It consists of two sub-atomic particle namely proton and neutron.
- These sub-atomic parts are tightly packed in nucleus which makes the nucleus dense .
- This dense nucleus is responsible for most of the mass of atom.
- The atomic mass for any atom is decided by sum of the mass of proton and neutron
Thus, correct answer is
(B) tightly packed protons and neutrons
Answer:
acceleration = 45 m/s²
Time = 20 seconds
Explanation:
We are given;
Distance; s = 90m
Final velocity;v = 90 m/s
Since shot from rest, initial velocity;u = 0 m/s
So, to find the acceleration, we can use Newton's 2nd law of motion which is;
v² = u² + 2as
Where a is acceleration
Plugging in the values;
90² = 0² + 2a(90)
8100 = 180a
a = 8100/180
a = 45 m/s²
Now, for the time, we will use Newton's 1st law of motion which is;
v = u + at
Where t is time;
So;
90 = 0 + 4.5t
90 = 4.5t
t = 90/4.5
t = 20 seconds
