Answer:
The answer is C because they have to be close to be able to interact
Answer: The original temperature was

Explanation:
Let's put the information in mathematical form:





If we consider the helium as an ideal gas, we can use the Ideal Gas Law:

were <em>R</em> is the gas constant. And <em>n</em> is the number of moles (which we don't know yet)
From this, taking
, we have:
⇒
Now:
⇒
Complete question:
Two 10-cm-diameter charged rings face each other, 21.0 cm apart. Both rings are charged to +40.0 nC. What is the electric field strength at the midpoint between the two rings ?
Answer:
The electric field strength at the mid-point between the two rings is zero.
Explanation:
Given;
diameter of each ring, d = 10 cm = 0.1 m
distance between the rings, r = 21.0 cm = 0.21 m
charge of each ring, q = 40 nC = 40 x 10⁻⁹ C
let the midpoint between the two rings = x
The electric field strength at the midpoint between the two rings is given as;

Therefore, the electric field strength at the mid-point between the two rings is zero.
The mass of an object on Earth is the same as its mass on the Moon. The weight is different.
Weight = m * g
Weight ( Moon ) = 40 kg * 1.6 m/s² = 64 N
If the mass of an object on Earth is 40 kg, its mass on the Moon is 40 kg and its weight on the Moon is 64 N.