Answer:B.As the north pole of the electromagnet nears the south pole of the permanent magnet, the current reverses and the poles of the magnets then repel.
Explanation:
<h2>
The asteroid is 4.11 x 10¹¹ m far from Sun</h2>
Explanation:
We have gravitational force

Where G = 6.67 x 10⁻¹¹ N m²/kg²
M = Mass of body 1
M = Mass of body 2
r = Distance between them
Here we have
M = Mass of Sun = 1.99×10³⁰ kg
m = Mass of asteroid = 4.00×10¹⁶ kg
F = 3.14×10¹³ N
Substituting

The asteroid is 4.11 x 10¹¹ m far from Sun
Answer: An acid is a substance that donates a proton and produces a conjugate base.
Explanation:
According to Bronsted-Lowry theory, an acid is a substance that donates a proton and produces a conjugate base while a base is a molecule or ion which accepts the proton.
An example of Bronsted-Lowry acid and base is Ethanoic acid, CH3COOH and hydroxide ion, OH- respectively as shown in the reaction below
CH3COOH(aq) + OH-(aq) <---> CH3COO-(aq) + H2O(l)
Thus, ethanoic acid acts as an acid by donating a proton to the hydroxide ion which accepts it, thus producing ethanoate ion, CH3COO- as a conjugate base.
I think the correct answer is C