Which of the following real-world examples models linear motion? a. throwing a rock in the air at a 60-degree angle b. throwing a rock in the air at a 45-degree angle c. running 50 m along a straight track d. running around the curve of a track

Option C, Running 50 m along a straight track

Explanation:

Linear motion is one directional motion which requires only one dimension to explain it. This motion is along a straight line.  

In all other options either the motion is taking place along a curved path(as in option D) , thereby making it a curvilinear motion or the motion is taking place at some angle (as in option A and B) thereby making it angular motion.

hence, option C is correct.

answer; ///as energy flows through an ecosystem,energy (decreases) at each

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c