If a cars velocity is slowing down is it considered a positive or negative acceleration?
1 answer:
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Answer:
The correct answer is A
Explanation:
The question requires as well the attached image, so please see that below.
Coulomb's Law.
The electrical force can be understood by remembering Coulomb's Law, that describes the electrostatic force between two charged particles. If the particles have charges and
, are separated by a distance r and are at rest relative to each other, then its electrostatic force magnitude on particle 1 due particle 2 is given by:
Thus if we decrease the distance by half we have
So we get
Replacing we get
We can then multiply both numerator and denominator by 4 to get
So we have
Thus if we decrease the distance by half we get four times the force.
Then we can replace the second condition
So we get
which give us
Thus doubling one of the charges doubles the force.
So the answer is A.
Answer:
the smallest separation between two objects is 0.8067 m
Explanation:
Given the data in the question;
Altitude h = 5.75 km = 5750 m
Diameter D = 4.0 mm = 0.004 m
λ = 460 nm = 4.6 × 10⁻⁷ m
Now, Using Rayleigh criterion for Airy disks resolution.
we know that, Minimum angular separation for resolving two points is;
θ = 1.22λ / D
so we substitute
θ = (1.22 × 4.6 × 10⁻⁷) / 0.004
θ = 5.612 × 10⁻⁷ / 0.004
θ = 1.403 × 10⁻⁴ rad
so minimum separation = θh
so we substitute
= (1.403 × 10⁻⁴) × 5750 m
= 0.8067 m
Therefore, the smallest separation between two objects is 0.8067 m