Answer:
c. V = k Q1 * Q2 / R1 potential energy of Q1 and Q2 separated by R
V2 / V1 = (R1 / R2) = 1/4
V2 = V1 / 4
Answer:
Because the light reflects multiple times until it gets to the Cassegrain focus.
Explanation:
The Cassegrain design can be seen in a reflecting telescope. In this type of design the light is collected by a concave mirror, and then intercepted by a secondary convex mirror, and sends it down to a central opening in the primary mirror (concave mirror), in which a detector is placed (Cassegrain focus)
Since, the light is reflected many times due to Cassegrain design, that leads to shorter telescopes.
Answer: a) 8.2 * 10^-8 N or 82 nN and b) is repulsive
Explanation: To solve this problem we have to use the Coulomb force for two point charged, it is given by:

Replacing the dat we obtain F=82 nN.
The force is repulsive because the points charged have the same sign.
Answer:
The number of paces it would take to get to the Moon is 213,555,556 paces
Explanation:
The given length of Mr Galan's paces = 1.8 m/pace
The distance from the Earth to the Moon is, 384,400 km = 384,400,000 m
Therefore, the number of paces, "n", it would take to get to the Moon from the Earth is given as follows;
n = (The distance from the Earth to the Moon)/(The length of each Mr Galan's paces)
∴ n = 384,400,000 m/(1.8 m/pace) = 213,555,556 paces
The number of paces it would take to get to the Moon = n = 213,555,556 paces
The spring has been stretched 0.701 m
Explanation:
The elastic potential energy of a spring is the potential energy stored in the spring due to its compression/stretching. It is calculated as

where
k is the spring constant
x is the elongation of the spring with respect to its equilibrium position
For the spring in this problem, we have:
E = 84.08 J (potential energy)
k = 342.25 N/m (spring constant)
Therefore, its elongation is:

Learn more about potential energy:
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