800-kg roller coaster moving down on a frictionless inclined plane at an inclined angle 25 degree.
Calculate
1. Weight ( force due to gravity)
2.Horizontal and vertical component of the weight
3.Normal force
4. Net force along the plane down
5.Acceleration

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:

like poles repel so keep pushing north to north and repels funny to see this

f=ma newton

f=100x2.5=250n