4) A crate is at rest on an inclined plane. As the slope increases the crate remains at rest until the incline reaches an angle of 32.7°from the horizontal. At this angle the crate
begins to slide down the ramp.
A) What is the coefficient of static friction between the crate and the surface of the
ramp?
B) If the coefficient of kinetic friction between the surface of the ramp and the crate is

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: