It takes twice the force to produce the same acceleration in the 2kg rock.
Answer:
0.073 N-m
Explanation:
i = 12 A, l = 0.8 m, B = 0.12 T
The circumference of the loop is 0.8 m.
Let r be the radius of the loop.
2 x 3.14 x r = 0.8
r = 0.127 m
Maximum Torque = i x A x B
Maximum Torque = 12 x 3.14 x 0.127 x 0.127 x 0.12 = 0.073 N-m
Answer:
(a) 
(b) neither increasing or decreasing
(c) opposite to the flow of charge carriers
Explanation:
The current through an inductor of inductance L is given by:
(1)
(a) The induced emf is given by the following formula
(2)
You derivative the expression (1) in the expression (2):

(b) At t=0 the current is zero
(c) At t = 0 the emf is:

w, L and Imax have positive values, then the emf is negative. Hence, the induced emf is opposite to the flow of the charge carriers.
(d) read the text carefully
Answer:

Explanation:
The inital electrostatic force between the two spheres is given by:

where
is the initial force
k is the Coulomb's constant
q1 and q2 are the charges on the two spheres
r is the distance between the two spheres
The problem tells us that the two spheres are moved from a distance of r=20 cm to a distance of r'=10 cm. So we have

Therefore, the new electrostatic force will be

So the force has increased by a factor 4. By using
, we find
