This is false. Current is the speed of the charge, 1 amp of current is 1 coulomb per second. So you can imagine the current of a circuit as the current of a river. In a parallel circuit, the river breaks into two separate streams. Some of the water goes down one river, some goes down the other. However, the total amount of water/coulombs never changes. This means that some of the total current will go down one river, and one the other. However, with less coulombs now the current will decrease.
Long story short, since there are two paths, the charge will split and depending on the resistance of each parallel stream a different amount of charge will go down each branch.
The sleds speed when the spring returns toits uncompressed length is v = 0.03 m/s.
<u>Explanation</u>:
Given,
force constant = 42 N/cm = 0.42 N/m, mass m = 68 kg, spring x = 0.39 m
The potential energy, U, stored in the spring is
U = 1/2 kx^2
= 1 / 2 
0.42 (0.39)^2
= 0.032 J
All its potential energy has been converted into kinetic energy since it has a uncompressed length.
K = 1/2 mv^2
v = sqrt (2K / m)
= √(( 2 0.032) / 68)
v = 0.03 m/s
.
That would be c. :) :) :)
I would say the correct answer would be light travels faster in medium 3 then medium 2.
