Let's say we have four different heights on a marble roller coaster:  1. At the top: .75 meters 2. After the first drop: .2 meters 3. At the top of the loop: .5 meters 4. Before the jump: .1 meters.  The value for gravity is 9.8 meters / second squared; the mass of the marble is .002 kilograms.  Find the Potential Energy at each point on the track: 

Which diagram correctly demonstrates the various forces acting on a ball moving horizontally with some speed?

Sawyer is studying diffraction. he draws a diagram of a plane wave to show how light waves travel. which best describes sawyer’s error? the wave fronts should be perpendicular to the direction in which the waves move. the arrow showing the direction of movement of the waves should be pointing to the left. the arrow showing the direction of movement of the waves should be pointing downward. the wave fronts should be both parallel and perpendicular to the direction in which the waves move.

Amira pulls a 3 pound wagon 4 feet. how much work has she done?