A sky diver of mass 70 Kg, and cross sectional area of 0.2 m2 is falling under gravity. Calculate the terminal velocity of this person. (Assume C= 0.88 kg/m3).

The terminal velocity of this person = 79.77 m/s

Explanation:

For a body falling through a fluid such as air, the forces acting on the diver include the force of gravity and the drag force.

And the net force is responsible for the acceleration of the diver.

Net force = mg - Drag force

But at terminal velocity, there's no acceleration and net force = 0

Hence, mg = Drag force

Drag force is given by CρAv²/2

where C = drag coefficient = 0.88

ρ = density of the fluid = density of air = 1.225 kg/m³

A = Cross sectional Area facing the fluid = 0.2 m²

v = velocity of the diver = ?

mg = 70 × 9.8 = 686 N

686 = (0.88×1.225×0.2×v²)/2

v² = (686×2)/(0.88×1.225×0.2)

v² = 6363.64

v = 79.77 m/s

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: