The sun <u><em>appears</em></u> brighter than any other star.
(It isn't really, but it looks that way because it's much much much much much much closer to us than any other star.)
You have to use the specific heat equation.
Q = cmΔT where Q is the energy, c is specific heat, m is mass, and ΔT is change in temp.
So we can substitute our variables into the equation.
30000J = (390g)(3.9J*g/C)ΔT
Solving for ΔT, we get:
30000J/[(390g)*(3.9J*g/C) = ΔT
ΔT = 19.72386588C
I'm assuming the temperature is C, since it was not specified.
Hope this helps!
Answer:
Vector quantities are important in the study of motion. Some examples of vector quantities include force, velocity, acceleration, displacement, and momentum. The difference between a scalar and vector is that a vector quantity has a direction and a magnitude, while a scalar has only a magnitude. Vector, in physics, a quantity that has both magnitude and direction. It is typically represented by an arrow whose direction is the same as that of the quantity and whose length is proportional to the quantity's magnitude. A quantity which does not depend on direction is called a scalar quantity. Vector quantities have two characteristics, a magnitude and a direction. The resulting motion of the aircraft in terms of displacement, velocity, and acceleration are also vector quantities. A vector quantity is different to a scalar quantity because a quantity that has magnitude but no particular direction is described as scalar. A quantity that has magnitude and acts in a particular direction is described as vector.
Explanation:

Strength: able to detect planets in a wide range of orbits, as long as orbits aren't face on
Limitations: yield only planet's mass and orbital properties