Answer:
protons
atomic number
Note: The same atomic number can be associated with several different values of atomic mass, but an element can have only 1 atomic number,
Answer:
red shift, indicating that the universe is expanding
Explanation:
Doppler effect occurs when a source of a wave (e.g. light, or sound waves) moves relative to an observer; as a result of this relative motion, the wavelength of the wave appears lengthened/shortened to the observer. Two situations can occur:
- The source of the wave is moving towards the observer - in this case, the wavelength of the wave becomes shorter. If the wave is visible light, such as the light emitted by distant galaxies, this means that the wavelength of the light shifts towards the blue-end of the spectrum (blue-shift)
- The source of the wave is moving away from the observer - in this case, the wavelength of the wave becomes longer. If the wave is visible light, such as the light emitted by distant galaxies, this means that the wavelength of the light shifts towards the red-end of the spectrum (red-shift)
In our universe, we observe a red-shift for all the distant galaxies: this means that these galaxies are moving away from us, so this is an indication that the universe is expanding.
Answer:
Explanation:
initial velocity, u = 8 m/s
vertical height, h = 1 m
θ = 40°
Let the horizontal distance is d and the time taken is t.
Use second equation of motion in vertical direction
h = ut + 1/2 at²
1 = 8 Sin 40 x t + 0.5 x 9.8 t²
1 = 5.14 t - 4.9t²
4.9t² - 5.14 t + 1 = 0
so, t = 0.26 s (smaller value)
So, the horizontal distance is
d = u cos 40 x t
d = 8 cos 40 x 0.26
d = 1.6 m
The 1st quadrant (0-90 degrees) is the only quadrant where none of the components are negative, so that means that any angle larger than 90 degrees will result in one of the components being negative.
