The correct option is C) The angle between the vectors is 120°.
Why?
We can solve the problem and find the correct option using the Law of Cosine.
Let A and B, the given two sides and R the resultant (sum),
Then,
So, using the law of cosines, we have:
Hence, we have that the angle between the vectors is 120°. The correct option is C) The angle between the vectors is 120°
Have a nice day!
Answer:
B. An isothermal compression of an ideal gas.
Explanation:
The internal energy of an ideal gas is just function of the temperature; it does not matter what other thermodynamic property changes, if the temperature does not change, the internal energy neither does. That is just for ideal gases; real gases behaviour is not like that. All of the other options bring with them an increase or decrease of the temperature:
For A, the temperature will decrease because the gas will do work as it expands, converting part of his internal energy to work.
For C, the temperature will increase, because given 
, if the volume increases (expansion) and the pressure is constant, the temperature must increase to satisfy the equation.
Answer:
Coefficient of kinetic friction = 0.146
Explanation:
Given:
Mass of sled (m) = 18 kg
Horizontal force (F) = 30 N
FInal speed (v) = 2 m/s
Distance (s) = 8.5 m
Find:
Coefficient of kinetic friction.
Computation:
Initial speed (u) = 0 m/s
v² - u² = 2as
2(8.5)a = 2² - 0²
a = 0.2352 m/s²
Nweton's law of :
F (net) = ma
30N - μf = 18 (0.2352)
30 - 4.2336 = μ(mg)
25.7664 = μ(18)(9.8)
μ = 0.146
Coefficient of kinetic friction = 0.146
The correct answer is <u>B. Where crust is destroyed.</u>
Answer:
The moist air mass would be denser
Explanation:
Density is defined as mass per unit volume. Hence the density of a substance (solid, liquid or gas) is directly proportional to its mass and inversely proportional to the volume occupied.
The mass of a gas is the product of its number of moles and its molar mass (mass = number of moles × molar mass), which indicates that the mass is directly proportional to molar mass, so the higher the molar mass, the higher the mass of different gases at equal volumes, temperature and pressure.
From the information given, the molar weight of dry air = 29g/mole.
The molar weight of moist air = molar weight of dry air + molar weight of water vapour = 29 + 18 = 47g/mole.
Therefore since higher molar mass transits to higher mass, it can be said that moist air of molar mass 47g/mole is denser than dry air of molar mass 29g/mole at equal volume, temperature and pressure.
Simple picture the two gasses in two transparent jars, the heavier gas (moist air) settles more at the bottom of the jar, and has less random motion hence is more compressed and denser, than dry air that has more freedom to move randomly because of its lesser weight.
