Answer:
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Explanation:
The basic relationship between frequency of an electromagnetic wave and wavelength of the wave is

where

is the speed of light.
Manipulating the equation, we can rewrite it as

The frequency of the wave in our problem is

so if we use the previous formula, we find the correspondant wavelength:
(a) The stone moves by uniform accelerated motion, with constant acceleration

directed downwards, and its initial vertical position at time t=0 is 750 m. So, the vertical position (in meters) at any time t can be written as

(b) The time the stone takes to reach the ground is the time at which the vertical position of the stone becomes zero: y(t)=0. So, we can write

from which we find the time t after which the stone reaches the ground:

(c) The velocity of the stone at time t can be written as

because it is an accelerated motion with initial speed zero. Substituting t=12.37 s, we find the final velocity of the stone:

(d) if the stone has an initial velocity of

, then its law of motion would be

and we can find the time it needs to reach the ground by requiring again y(t)=0:

which has two solutions: one is negative so we neglect it, while the second one is t=11.78 s, so this is the time after which the stone reaches the ground.
Answer:
1.
Explanation:gamma rays are the most powerful in the electromagnetic spectrum and they are a result of a radioactive atom.they aren't made of matter but just energy as a wave.
Answer:
B) the law of reflection
Explanation:
When a light ray reflects off a surface, it obeys the law of reflection.
A few definitions before giving the law of reflection:
- The angle of incidence is defined as the angle between the incident ray and the normal to the surface
- The angle of reflection is defined as the angle between the reflected ray and the normal to the surface
The law of reflection states that:
- The angle of incidence is equal to the angle of reflection
- The incident ray and the reflected ray lie both on the same plane.