Two cannons of mass 100 kg are placed on a uniform disc of radius 4.0 m and mass 400 kg. one cannon is located at the edge of the disc and the other cannon is placed on the opposite side of the disc half way between the center of the disc and the edge. the two cannons fire simultaneously in the same direction (toward the left). the cannonballs each have a mass of 2.0 kg and are moving at 250 m/s.

a. what is the angular velocity of the disc after the cannons are fired? is it rotating clockwise or counterclockwise?

b. suppose we could stop the rotation of the disc by firing a third cannonball. which cannon must fire and how fast must the cannonball be moving?

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

force tends to be low and long diustance masses are high

answergravity;