# Homework Help: Power balance analysis of some motor and generator

1. Jun 10, 2007

### freeboo

1. The problem statement, all variables and given/known data
1. Motor/generator. In the bar and rail problem shown in Figure 1, the bar moves at a constant
velocity of 6 m/s to the right. There is uniform magnetic field of 0.75 T oriented downward, as shown,
in the space between the rails. The mass of the bar is 500 g, and the coefficient of kinetic friction is 0.05μ. The bar’s internal resistance is 0.01Ω .
(a) With the switch in position 1
(i) Determine the magnitude and direction of the current in the circuit
(ii) Determine the magnitude and direction of the externally applied force on the bar that would
be necessary to maintain a constant velocity, and state (give written reasoning) whether the bar is acting
as a motor or a generator.
(iii) Perform a complete power balance analysis of the system
(b) Repeat steps (i),(ii),(iii) with the switch in position 2
(c) Repeat steps (i),(ii),(iii) with the switch in position 3

the fig is on they link

2. Relevant equations

3. The attempt at a solution

Last edited by a moderator: May 2, 2017
2. Jun 10, 2007

### malawi_glenn

guess why "2. Relevant equations" and "3. The attempt at a solution" exists?...