A72.0 kg man stands on a spring scale in an elevator. starting from rest, the elevator ascends, attaining its maximum speed of 1.70 m/s in 1.20 s. it travels with this constant speed for the next 5.00 s. the elevator then undergoes a uniform acceleration in the negative y-direction for 1.80 s and comes to rest.(a) what does the spring scale register before the elevator starts to move? (b) what does it register during the first 1.20 s? (c) what does it register while the elevator is traveling at a constant speed? (d) what does it register during the time it is slowing down?

82.39 kg

72 kg

62.07 kg

Explanation:

Force on the scale would be

The scale would register 82.39 kg when going up

When the speed becomes constant the acceleration becomes 0. So, the scale would show 72 kg in the five seconds

Force on scale

The scale would show 65.07 kg while going down.

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:

d.7.5cm is your answer