Acopper wire of length 16 cm is in a magnetic field of 0.19 t. if it has a mass of 9.0 g, what is the minimum current through the wire that would cause a magnetic force equal to its weight?

2.9 A

Explanation:

L = 16 cm = 0.16 m

B = 0.19 T

m = 9 g = 0.009 kg

Let the minimum current be i.

Magnetic force is balanced by the gravitational force

B x i x L = m x g

0.19 x i x 0.16 = 0.009 x 9.8

i = 2.9 A

1= 26.17

2= 1.17

3=30.86

4=5.86

just took the assigment on edge

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form