Answer:
(a) The current should be in opposite direction
(b) The current needed is 39.8 A
Explanation:
Part (a)
Based, on right hand rule, the current should be in opposite direction
Part (b)
given;
strength of magnetic field, B = 370 µT
distance between the two parallel wires, d = 8.6 cm
At the center, the magnetic field strength is twice
R = d/2 = 8.6/2 = 4.3 cm = 0.043 m
Therefore, current needed is 39.8 A
Answer: d= 0.57* l
Explanation:
We need to check that before ladder slips the length of ladder the painter can climb.
So we need to satisfy the equilibrium conditions.
So for ∑Fx=0, ∑Fy=0 and ∑M=0
We have,
At the base of ladder, two components N₁ acting vertical and f₁ acting horizontal
At the top of ladder, N₂ acting horizontal
And Between somewhere we have the weight of painter acting downward equal to= mg
So, we have N₁=mg
and also mg*d*cosФ= N₂*l*sin∅
So,
d= * tan∅
Also, we have f₁=N₂
As f₁= чN₁
So f₁= 0.357 * 69.1 * 9.8
f₁= 241.75
Putting in d equation, we have
d= * tan 58
d= 0.57* l
So painter can be along the 57% of length before the ladder begins to slip