<span>a) 13 seconds
b) 130 m/s
The formula for the distance an object moves while under constant acceleration is d = 1/2AT^2. So let's define d as 830 m, A as 9.8m/s^2, and solve for T
830 m = 1/2 9.8 m/s^2 T^2
830 m = 4.9 m/s^2 T^2
Divide both sides by 4.9 m/s^2
169.3878 s^2 = T^2
Take the square root of both sides
13.01491 s = T
Since we only have 2 significant figures, round the result to 13 seconds which is the answer to the first part of the question. To find out how fast the marble is moving, just multiply T and A together
13 s * 9.8 m/s^2 = 127.4 m/s
Since we only have 2 significant figures, round the result to 130 m/s.</span>
Answer:
The speed of the galaxy relative to the Earth is
.
Explanation:
We have,
(a) Wavelength emitted by light at distant galaxy is 434.1 nm. On earth, the wavelength of this light is measured to be 438.6 nm. It can be seen that the wavelength of light reduces as it reaches Earth. It is called Red shift. As per Doppler's effect, we can say that the galaxy is receding from the Earth.
(b) Let v is the speed of the galaxy relative to the Earth. It can be given by :

So, the speed of the galaxy relative to the Earth is
.
B is the correct answer
y=Asin(wt-kx)
A=amplitude
f=frequency
x=wavelength
since refraction is not on the wave formula,then option B is the correct answer
Answer:
Ionic Compound
Explanation:
To identify the type of chemical bond in a molecule, look at the atoms that make up the compound. If there are two nonmetals, it is a covalent bond. If the two atoms are metals, it is a metallic bond. If one atom is a metal and the other is a nonmetal, it is an ionic bond. Ionic compounds are also known as salts. You can identify KBr as an ionic compound because potassium is a metal and a salt.
Hope this helps
Answer:
<em>A. Statistics addresses gaps in knowledge.</em>
Explanation:
The following statements that does not describe a limitation of statistics is <em>statistics addresses gaps in knowledge.</em>