The principle characteristic distinguishing marine and freshwater ecosystems is a. temperature b. presence of corals c. presence of fish d. dissolved salt

What is the primary force that suspension bridges use cables to hold their spans up? a. tension force b. resistance force c. normal force d. elastic force e. applied force

Sound is a disturbance that travels through a medium as a

Amother used 150 watts of power to raise a 15 newton object in a time interval of 8.0 seconds. through what vertical distance was the object raised ?