<span>B) 0.6 N
I suspect you have a minor error in your question. Claiming a coefficient of static friction of 0.30N is nonsensical. Putting the Newton there is incorrect. The figure of 0.25 for the coefficient of kinetic friction looks OK. So with that correction in mind, let's solve the problem.
The coefficient of static friction is the multiplier to apply to the normal force in order to start the object moving. And the coefficient of kinetic friction (which is usually smaller than the coefficient of static friction) is the multiplied to the normal force in order to keep the object moving. You've been given a normal force of 2N, so you need to multiply the coefficient of static friction by that in order to get the amount of force it takes to start the shoe moving. So:
0.30 * 2N = 0.6N
And if you look at your options, you'll see that option "B" matches exactly.</span>
A transformer is used to increase or decrease a voltage. BUT ... it has to be an AC voltage, or the transformer doesn't work.
Answer:
80%
Explanation:

800 / 1000 = 0.8
Efficiency = 0.8 *100 = 80%
Answer:
0.01606 Newtons
Explanation:
r = Distance between the asteroid and Sally = 17000000 m
m₁ = Mass of the asteroid = 8.7× 10²⁰ kg
m₂ = Mass of Sally = 80 kg
G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²
From Newton's Universal law of gravity

The force Sally experiences is 0.01606 Newtons