1) The equivalent resistance of two resistors in parallel is given by:

so in our problem we have

and the equivalent resistance is

2) If we have a battery of 12 V connected to the circuit, the current in the circuit will be given by Ohm's law, therefore:
Answer:
The volume of copper is 2.198 ml
Explanation:
Given;
mass of copper, m = 20 g
density of copper, ρ = 9.1 g/ml
Density is given by;
Density = mass / volume
Volume = mass / density
Volume = (20 g) / (9.1 g/ml)
Volume = 2.198 ml
Therefore, the volume of copper is 2.198 ml
From the concept of optics on a curvature of a spherical mirror, the proportion for which the focal length is equivalent to half the radius of curvature is fulfilled. Mathematically this is

Here,
f = Focal Length
R = Radius
Rearranging to find the radius we have,

Replacing with our values,
R = 2(13.8cm)
R = 27.6cm
Therefore the radius of the spherical surface from which the mirror was made is 27.6cm
The magnitude of the air drag is 784 N
Explanation:
An object falling down reaches the terminal velocity when the magnitude of the air drag acting on it becomes equal to the weight of the object. Mathematically, this condition can be written as:

where
is the magnitude of the air drag
m is the mass of the object
g is the acceleration of gravity
In this problem, we have
m = 80 kg is the mass of the airman
is the acceleration of gravity
Substituting into the formula, we find:

Learn more about forces here:
brainly.com/question/8459017
brainly.com/question/11292757
brainly.com/question/12978926
#LearnwithBrainly
This is the answer to what a hypothesis may also be called