Gravitational potential energy (u) depends on three things: the object’s mass (m), its height (h), and gravitational acceleration (g), which is 9.81 m/s2 on earth’s surface: u = mgh energy is measured in joules (j). one joule is equal to one 1 kg•m2/s2. when calculating the energy of an object, it is to convert the mass and height to kilograms and meters. a. what is the mass of the 50-gram car, in kilograms? b. set hill 1 to 75 cm and the other hills to 0 cm. what is the height in meters? c. what is the potential energy of the car, in joules?

Explanation:

A. Mass of the car ,m = 50 g

1 g = 0.001 kg

50 g = 0.001 × 50 kg = 0.05 kg

B. Height of hill ,h= 75 cm = 0.75 m

1 cm = 0.01 m

Height of other hill ,h' = 0 cm = 0 m

C. Gravitational potential energy (U):

Mass of car = m = 0.05 kg

Height at which car is = h = 0.75 m

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: