A helicopter of mass 1.40×103kg1.40×103kg is descending vertically at 3.00 m/sm/s. The pilot increases the upward thrust provided by the main rotor so that the vertical speed decreases to 0.450 m/sm/s as the helicopter descends 3.00 mm. What is the initial energy of the helicopter?

KE=6300 J

Explanation:

Given that

mass of the helicopter , m = 1.4 x 10³ kg

Initial velocity , u = 3 m/s

Velocity after increasing thrust , v = 0.45 m/s

Distance , d= 3 mm

The initial kinetic energy KE is given as follows

Now by putting the values in the above equation we get

KE=6300 J

Therefore the initial energy of the helicopter will be 6300  J.

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: