Suppose that the voltage of the battery in the circuit is 3.9 V, the magnitude of the magnetic field (directed perpendicularly into the plane of the paper) is 1.1 T, and the length of the rod between the rails is 0.22 m. Assuming that the rails are very long and have negligible resistance, find the maximum speed attained by the rod after the switch is closed.

v = 16.11 m/s

Explanation:

In order to calculate the maximum speed of the rod, you use the following formula:

       (1)

ε = voltage of the circuit = 3.9V

v: maximum speed of the rod = ?

B: magnitude of the magnetic field = 1.1T

L: length of the rod = 0.22m

θ: angle between the direction of motion of the rod and the direction of the magnetic field = 90°

You solve the equation (1) for v and replace the values of the other parameters:

The maximum speed of the rod is 16.11 m/s

given data:

determine the horse power (h.p) = ?

force applied to move the box(f) = 10 pounds,

box lifted from a distance         (d) = 3 feet

time taken to lift                         (t) = 10 sec,

the horse power is defined as amount of work required to move a load. the horse power is equal to 550 foot-pound per second

                  1 h.p   = 550 foot-pound/second

it can also be defined as the the load that need to be move a body for certain distance in a certain amount of time.

mathematically,

                      h.p = (force × distance)/ time

                            = (10 × 3)/ 10

                            = 30/10

                            = 3 foot -pound/sec

hence, the horse power is needed to move the box is 3 foot-pound/second

important note: 1 h.p = 550 foot-pound/second = 746 watts

elctricity and magnet is conversion to it