Answer:

Explanation:
Given data
mass of copper m=4.85 kg
charge of electron qe= -1.6×10⁻¹⁹C
To find
Number of electron n must be removed
Solution
Equate the magnitude of electric force Fe of repulsion between two two spheres to the magnitude of gravitational force of attraction between them
So

where q is charge of each sphere which is equal to number n of removed electrons multiplied by each charge qe
So

Distance = velocity (or speed) x time
so, distance = 0.30 meters.min x 15 mins
distance = 4.5 meters
Answer:
I think that's Newton's second law of motion
Explanation:
f = m(v-u)
________
t
since a = (v-u)t
f = ma
Answer:
When the elevator is accelerating downward, the person feels lighter due to the downward normal force being less than the person's weight.
Explanation:
A person riding in an elevator subjected to a series of unbalanced forces depending on the direction the elevator is travelling.
Two forces are acting on the person; the force of gravity and the upward normal force from the elevator.
When the elevator is going upwards with acceleration a, the person feels heavier than his normal weight, due to the upward normal force being greater than the person's weight. N = mg + ma
When the elevator is moving downwards with acceleration a, the person feels lighter due to the downward normal force being less than the person's weight. N = mg - ma
However, when the elevator is moving up or down at constant velocity ie. acceleration a = 0, the person experience a normal force equal to weight. N = mg
When the elevator is moving downwards with acceleration a = g, the person experiences weightlessness. N = (mg - mg) = 0
32? I could be wrong but I’m going with that answer choice