Answer:
0.0979 N/c
Explanation:
Electric field, E is given as a product of resistivity and current density
E=jP where P is resistivity and j is current density
But the current density is given as
where I is current and A is area and 
Substituting this into the first equation then 
Given diameter of 0.259 cm= 0.00259 m and the radius will be half of it which is 0.001295 m

Answer:
a) t = 1.6 s
b) d = 4.9 m
c) v = 16 m/s
d) θ = 79°
Explanation:
time of fall
t = √(2h/g) = √(2(12)/9.8) = 1.5649... s
d = vt = 3.1(1.56) = 4.8512...
vertical velocity vy = at = 9.8(1.56) = 15.336... m/s
v = √(15.336² + 3.1²) = 15.6464... m/s
θ = arctan(15.336/3.1) = 78.5724...°