Answer:
v = 0.489 m/s
Explanation:
It is given that,
Mass of a box, m = 1.5 kg
The compression in the spring, x = 6.5 cm = 0.065 m
Let the spring constant of the spring is 85 N/m
We need to find the velocity of the box (v) when it hit the spring. It is based on the conservation of energy. The kinetic energy of spring before collision is equal to the spring energy after compression i.e.
So, the speed of the box is 0.489 m/s.
If you throw water on anything hot enough, the liquid water turns to steam. With this method, you can create an energy source.
Answer:
Only option A is correct
Explanation:
From the concept of Doppler effect, only speed matters. Thus, the faster a vehicle is moving, the closer together the sound waves get compressed and the higher the frequency. For example, for a very fast vehicle traveling at the speed of sound; the compressions are all right on top of each other. Thus, faster speed means closer compressions and higher frequencies. Hence, option only option A must be true because X is a higher frequency and so it must be going faster. The distance to the person will affect the volume but will not the pitch so Option B is not correct. Option C too is not correct because It doesn’t matter whether you are speeding up or slowing down, it only matters who is going faster. For example, from option c concept, if truck X was going 10 m/h and speeding up while truck Y was going 50 mph and slowing down, it would not meet the requirement that X has a higher frequency because only actual speed matters, not what is happening to that speed. Thus only option A is the correct answer
Answer:
The Balmer series refers to the spectral lines of hydrogen, associated to the emission of photons when an electron in the hydrogen atom jumps from a level 
to the level 
.
The wavelength associated to each spectral line of the Balmer series is given by:
where 
is the Rydberg constant for hydrogen, and where 
is the initial level of the electron that jumps to the level n = 2.
The first few spectral lines associated to this series are withing the visible part of the electromagnetic spectrum, and their wavelengths are:
656 nm (red, corresponding to the transition 
)
486 nm (green, 
)
434 nm (blue, 
)
410 nm (violet, 
)
All the following lines lie in the ultraviolet part of the spectrum. The limit of the Balmer series, corresponding to the transition 
, is at 364.6 nm.
