It is c convection because convection is when something is hot therefore less dense material to rise and cooler material to sink under the influence of gravity
Answer:
Measure the brightness of a star through two filters and compare the ratio of red to blue light. Compare to the spectra of computer models of stellar spectra of different temperature and develop an accurate color-temperature relation.
talk, make conversation. text isnt always the answer, but sadly now it is. text them or better yet, call them. you can talk and then do not just blurt it out. say it calmly. they say yes, congrats, but if they say no, do not have a mental breakdown. it might ruin a friendship.
Answer:
Explanation:
A chemical change.
Usually those are irreversible. Or they may be reversible, but the form they take may leave your object not the same as they started out.
A physical change might be just as deadly. If the object melted like a chocolate Easter Bunny then the object would be irreversible as well. Take a better example.
Suppose you are talking about a Gold Coin. If you heated it so it melted, the gold would retain its value, but the fact that it is a coin and valuable as such, means that it has lost that part of its value.
I really don't know. My instincts tell me that the chemical change is more dangerous, but I can't rule out the other choice..
Answer:
Approximately
to the right (assuming that both astronauts were originally stationary.)
Explanation:
If an object of mass
is moving at a velocity of
, the momentum
of that object would be
.
Since momentum of this system (of the astronauts) conserved:
.
Assuming that both astronauts were originally stationary. The total initial momentum of the two astronauts would be
since the velocity of both astronauts was
.
Therefore:
.
The final momentum of the first astronaut (
,
to the left) would be
to the left.
Let
denote the momentum of the astronaut in question. The total final momentum of the two astronauts, combined, would be
.
.
Hence,
. In other words, the final momentum of the astronaut in question is the opposite of that of the first astronaut. Since momentum is a vector quantity, the momentum of the two astronauts magnitude (
) but opposite in direction (to the right versus to the left.)
Rearrange the equation
to obtain an expression for velocity in terms of momentum and mass:
.
.
Hence, the velocity of the astronaut in question (
) would be
to the right.