82 ÷ 6.5 = 12.615384615384... repeating
round = 12.6
12.6 · 6.5 = 81.9
round = 82
She went an average of 12.6 km an hour
Hope this helps! ;)
Answer:
Thermal expansion ,thermal contraction
Explanation:
They are different because it has different cause and chemical reactions
thermal contraction is a chemical reaction
The latent heat of fusion refers to the solid to liquid or liquid to solid states.
Answer: Option C
<u>Explanation:
</u>
It is known that the inter conversion process from the states of solid to liquid is referred as fusion. So, for these conversions, the external energy in the heat form should be supplied to solid.
This external energy should be greater than the latent heat of solid in order to successfully break the bonds to form liquid. So the change in the enthalpy of the reaction while conversion from solids to liquids are termed as latent heats of fusion.
Even the inter-conversion from liquid to solid state will undergo change in enthalpy where the heat will be released and that is termed as latent heats of solidification. It is found that latent heat of solidification is equal in magnitude but opposite in direction with the latent heats of fusion.
Answer:
308,000 or 30.8×10^3
Explanation:
v=f×lamda
v is ?, f is 875Hz, lamda is 352m
v=875×352
v=308,000
v=30.8×10^3 m/s
Answer:
proof in explanation
Explanation:
First, we will calculate the number of half-lives:
where,
n = no. of half-lives = ?
t = total time passed = 2100 million years
= half-life = 700 million years
Therefore,
Now, we will calculate the number of uranium nuclei left (
):
and the rest of the uranium nuclei will become thorium nuclei (
)
dividing both:
<u>Hence, it is proven that after 2100 million years there are seven times more thorium nuclei than uranium nuclei in the rock.</u>
