Which is a false statement about the possible benefits of nanocars?

a. they could work together to build really complex things.
b. they could increase the efficiency of building computer chips.
c. they could increase the ability to build things from the top down.
d. they could work as medical submarines searching the body for disease.

An engineer designs a roller coaster so that a car travels horizontally for 152 ft, then climbs 137 ft at an angle of 34.0° above the horizontal. it then moves 137 ft at an angle of 48.0° 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.)