Scientists test their ideas by a. publishing in scientific journals b. performing experiments c. developing theories d. none of the above

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.)

What is relative velocity? in which condition is relative velocity known by adding the velocity of the first body and that of the second body

What is the measure of how much matter is in an object and that can be measured using a balance? a. height b. volume c. weight d. mass