Acar converts the chemical energy of gasoline to the mechanical energy of motion. the total energy of motion is less than the total energy stored in the gasoline. evidence that energy is still conserved, however, is found in which of the following observations?
a) the mass of the moving object, the car, is greater than that of the gasoline
b) the energy in the gasoline was extracted from crude oil, which had more energy.
c) some of the energy of the gasoline is also converted to heat and sound energy.
d) not all car engines are equally efficient at this energy transformation.

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.

chemical energy --> gravitational potential energy --> kinetic energy --> elastic potential energy --> gravitational potential energy

explanation:

when emma starts the hike, the chemical energy stored in her body is used to climb up the mountain, and so she gains gravitational potential energy (because at the end, she will be at a higher height h above the ground). then she goes bungee jumping: as she falls, this gravitational potential energy is converted into kinetic energy (because her speed increases as she falls down), until the point when the rope stretches, and she stops moving. at that moment, all the kinetic energy is converted into elastic potential energy due to the stretching of the rope. then, this energy is released because the rope returns to its natural length, and emma gains a small increase in altitude , so she gains some gravitational potential energy.