The initial force between the two charges is given by:

where k is the Coulomb's constant, q1 and q2 the two charges, d their separation. Let's analyze now the other situations:
1. F
In this case, q1 is halved, q2 is doubled, but the distance between the charges remains d.
So, we have:

So, the new force is:

So the force has not changed.
2. F/4
In this case, q1 and q2 are unchanged. The distance between the charges is doubled to 2d.
So, we have:

So, the new force is:

So the force has decreased by a factor 4.
3. 6F
In this case, q1 is doubled and q2 is tripled. The distance between the charges remains d.
So, we have:

So, the new force is:

So the force has increased by a factor 6.
There are two forces at play:
- The gravitational force acting downward due to the mass of the bucket and the water that it contains.
- The upward force that your hand exerts on the bucket.
If the magnitude of the force your hand exerts on the bucket equals the magnitude of the gravitational force, the bucket is in static equilibrium. That means the bucket is not moving and the forces acting on it balance each other out, making the net force 0.
Having 0 net force means the bucket doesn't undergo any acceleration, or change in motion.
Explanation:
By Hooke's Law,
F=kx
The only force acting here is weight, and x is the extension of the string (you need to convert this to mm) so
mg=kx
(0.15)(9.81)=k ((420-300)x10^-3)
Then just solve this equation.
Answer:
the weight of the ball is w = 51.94 N ( mass = 5.3 kg)
Explanation:
Following Newton's second law:
net force = mass * acceleration = weight/gravity * acceleration
then denoting 1 and 2 as the first and second lift
F₁ - w= w/g *a₁
F₂ -w = w/g *a₂ = w/g * 2.07a
dividing both equations
(F₂- w)/(F₁ -w)= 2.07
(F₂- w) = 2.07 * (F₁ -w)
1.07*w = 2.07*F₁ - F₂
w = (2.07*F₁ - F₂ )/ 1.07
replacing values
w = (2.07*61.1 N - 70.9 N )/ 1.07 = 51.94 N
then the weight of the ball is w = 51.94 N ( mass = 5.3 kg)