Answer:
a. the force between them quadruples
Explanation:
The electrostatic force between two charges is given by

where
k is the Coulomb's constant
q1 and q2 are the two charges
r is the separation between the two charges
In this problem, the charges on both objects are doubled, so

While the distance does not change, so the new force will be

so, the force will quadruple.
Given:
Uniform distributed load with an intensity of W = 50 kN / m on an overhang beam.
We need to determine the maximum shear stress developed in the beam:
τ = F/A
Assuming the area of the beam is 100 m^2 with a length of 10 m.
τ = F/A
τ = W/l
τ = 50kN/m / 10 m
τ = 5kN/m^2
τ = 5000 N/ m^2<span />
Answer:
B) how steep the slope is
Explanation:
Because you have to know how is the influence of the steep of the slope in the time that a ball reaches the bottom. The steep of the slope is the variable that you would have to change in an experiment.
I hope this is useful for you
regards
Potential energy at top:
PE = mgh
PE = 40 x 9.81 x 12
P.E = 4,708.8 J
Kinetic energy at bottom:
KE = 1/2 mv²
KE = 1/2 x 40 x 10²
K.E = 2,000 J
P.E = K.E + Frictional losses
Frictional losses = 4708 - 2000
Frictional losses = 2708 J
The answer is D.