The skateboarder weighs 75 kilogram. Calculate the potential energy of the skateboarder sliding on the track when his height above the ground is 5 meters. (Assume that acceleration due to gravity is 9.81m/s2.)

F(of gravity) = MA

F(normal force) = MA * cos(angle)

F = 72 * 9.81 * cos28

Don't have a calculator, so can't really do all the math right there. So just plug that in

Explanation:

i dont really know

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:

a electromagnetic waves