Answer:
No, the farmer is not able to move the mule.
Explanation:
Mass =100 kg
Force=F=800 N
The coefficient between the mule and the ground=

Static friction force,f=
Normal force=N=mg
Static friction force,f=
Using 
F<f
Static friction force is greater than applied force.
Therefore , the farmer is not able to move the mule.
Answer:
Electric Field = E = 36.848 N/C
Explanation:
In accordance with Columb's law
E = k Q1 Q2 / r.r = 8.99 x 10^9 x 5.0 x 10^-6 x 5.8 x 10^-6 / 0.084 x 0.084
= 36948.6961 x 10^-3 = 36.848 N/C
Here we can use momentum conservation as in this type of collision there is no external force on it

now here we can say




now here we can say


now by coefficient of restitution
for elastic collision we know that e = 1


now by solving the two equation


also we know that

so final speed of the nail is 6.875 m/s
Answer:
His gravitational potential energy will increase as well.
Explanation:
Let gpe represent gravitational potential energy.
gpe = mass × gravitational field strength × height
From the formula above, we can conclude that as the mass of a body increases, it's gpe increases too.