Answer:
Europium has a bright shiny surface. it's steel grey and has a melting point of 826 degree Celsius and a boiling point of about 1,489 degree Celsius.
Explanation:
the density is 5.24 grams per cubic centimeter.
The answer is 5.88 · 10⁻⁷<span> m.</span>
To calculate this we will use the light equation:
v = λ · f,
where:
v - the speed of light (units: m/s)
<span>λ - the wavelength of the ray (units: m)
</span>f - the frequency of the ray (units: Hz = 1/s <span>since Hz means cycles per second (f=1/T))
</span>
It is given:
f = 5.10 · 10¹⁴ Hz = 5.10 · 10¹⁴<span> 1/s
v = 2.998 </span>· 10⁸<span> m/s
</span><span>λ = ?
</span>
If v = λ · f, then λ = v ÷ f:
λ = 2.998 · 10⁸ m/s ÷ 5.10 · 10¹⁴ 1/s
= 0.588 · 10⁸⁻¹⁴ · m
= 0.588 · 10⁻⁶ m
= 5.88 · 10⁻⁷ m
Maybe when you ice-skate 10 times per second around a 1-foot circle.
Answer:
d. 0V
Explanation:
The magnitude of four point charges are +3q, -q, +2q and -4q. I think you forget to mention the signs.
As we know that the potential due to the point charge that has traveled the distance d can be represented mathematically as,

= 1/4λε = 9×
Nm²/C²
Now as it is mentioned in the question that all four charges are arranged in the corners of a square so there distance from the center is same. We can rewrite the above potential equation as follows.
(1)
We can find out d by the pythagoras theorem, as we are dealing with square so d is a semi diagonal.

by putting all values in equation (1)
V = 
V = 0V
Molten rock material wells up from the underlying mantle into the gap between the diverging plates and solidifies into oceanic crust, thereby creating new ocean floor. At the deep-sea trenches, two plates converge, with one plate sliding down under the other into the mantle where it is melted.:)