Complete Question:
Two small objects each with a net charge of Q (where Q is a positive number) exert a force of magnitude "F" on each other. We
replace one of the objects with another whose net charge is 4Q. The original magnitude of the force on the Q charge was "F"; what is the magnitude of the force on the Q charge now?
Answer:
4 F₀
Explanation:
Assuming that we can treat to both objects as point charges, we can find the force "F" that one charge exerts upon the other applying Coulomb´s law, as follows:
F₀ = K*Q₀² / r₁₂²
If we replace one of the charges by one with a 4Q₀ charge, the new value of F will be as follows:
F₁ = K*Q₀*4Q₀ / r₁₂² =( K*Q₀² / r₁₂²)* 4 = 4* F₀
This value is reasonable, as the electrostatic force is a linear - type one, so it is possible to use the superposition principle (we can get the force exerted by one charge on another without considering the ones due to another charges)
The best answer would be the 4th choice. "They help scientists explain concepts that are difficult to observe, this also covers the first answer which helps the scientist to answer complex questions. A scientific model is not used prove scientific laws as they may not always have all the data to prove so, instead it is used to allow them to explain better concepts revolving around science through research and may also allow them to predict results based on the accumulation of data and analyzing the trend of this resulting information.
Answer:
1%
Explanation: A cassegrain telescope is a kind of telescope which is made up of the curved mirrors one of the mirrors is a concave mirror is called the primary mirror and the second mirror called the secondary mirror which is a convex mirror, when light Penetrate the cassegrain telescope, it first hits the primary concave mirror and it's then reflected by the secondary convex mirror.
(1) The time of motion of the arrow is 0.25 s.
(2) The vertical height dropped by the arrow as it approaches the target is 0.31 m.
The given parameters:
- <em>Horizontal distance of the arrow, X = 20 m</em>
- <em>Horizontal speed of the arrow, v = 80 m/s</em>
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The time of motion of the arrow is calculated as follows;

The vertical height dropped by the arrow as it approaches the target is calculated as follows;

Learn more about time of motion of projectile here: brainly.com/question/1912408
Energy required = mass x specific heat x temperature difference
= 0.5 x 4.19x10^3 x 2
= 4190J