<span>Density is a value for
mass, such as kg, divided by a value for volume, such as m3. Density is a
physical property of a substance that represents the mass of that substance per
unit volume. Therefore, we calculate as follows:
density = mass / volume
density = 1 / </span>πr²h
density = 1 / π((39/2)^2)(39)
density = 1 / 46589.03
density = 2.15 x 10^-5 kg/mm^3
Answer:
There are two methods generally used to magnetize permanent magnets: static magnetization and pulse magnetization.
Explanation:
For projectile motion, use constant acceleration equation:
Δx = v₀ t + ½ at²
where Δx is the displacement,
v₀ is the initial velocity,
a is the acceleration,
and t is time.
Both objects are projected upward with velocity u. The second object is thrown after a time t₀.
For the first object:
Δx = u t + ½ (-g) t²
Δx = u t − ½g t²
For the second object:
Δx = u (t−t₀) + ½ (-g) (t−t₀)²
Δx = u (t−t₀) − ½g (t−t₀)²
Assuming the objects meet, the displacements will be equal:
u t − ½g t² = u (t−t₀) − ½g (t−t₀)²
u t − ½g t² = u (t−t₀) − ½g (t² − 2tt₀ + t₀²)
u t − ½g t² = u t − u t₀ − ½g t² + g tt₀ − ½g t₀²
0 = -u t₀ + g tt₀ − ½g t₀²
0 = -u + g t − ½g t₀
g t = u + ½g t₀
t = u/g + t₀/2
I think the correct answer would be the last option. A kind of variable that a researcher purposely changes in an investigation is the independent variable. It is the value that does not depend to any change in any variable involved. Instead, it is the one that affects the other variable called the dependent variable. The dependent variable is the variable that is being tested or studied. Also, along with these two there are variables that are held equal all through out the research. These are called the constants. These constants are factors that might affect the dependent variable that is why they are held constant to prevent more errors.
The answer is evolution. When a specifies evolves over time they change and adapt to their environment.
