Electro-magnets are created
a) applying a charge to a magnetic material, wrapped in an insulator, which creates an electro magnetic field around the magnet.
b) covering a magnet with insulation in applying an alternating electrical current to the magnet.
c) twisting a ferromagnetic material, wrapping in an insulator, and applying a direct current to the coil.
d) wrapping in insulated wire around a medal with ferromagnetic properties and applying an electric current.

An engineer designs a roller coaster so that a car travels horizontally for 162 ft, then climbs 127 ft at an angle of 31.0° above the horizontal. it then moves 127 ft at an angle of 46.0° below the horizontal. if we take the initial horizontal motion of the car to be along the +x-axis, what is the car's displacement? (give the magnitude of your answer, in ft, to at least four significant figures and give the direction of your answer in degrees counterclockwise from the +x-axis.)

Orange juice has a lower or higher viscosity than chocolate syrup

Which of the following is the result of the nuclear weak force? the instability of large nuclei the repelling force between positively charged protons the structure of the atom certain types of nuclear decay