Two cars are raised to the same elevation on service- station lifts. If one car is twice as massive as the other, how do their potential energies compare?

The potential energy of the more massive one is twice that of the other.

Explanation:

Potential energy is given by

PE = mgh

where m = mass of body, g = acceleration of gravity and h = height or elevation.

For the less massive car, let the mass be . Then its PE is

For the massive car, let the mass be .  Its PE is

But

Hence, the potential energy of the more massive one is twice that of the other.

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:

none, its a machine