Which statement is true?
a. kepler’s laws apply only to the motion of earth.
b. kepler’s laws can be used to predict eclipses.
c. kepler’s laws are true for a central force that is directly proportional to distance. d. kepler’s laws can be deduced from newton’s laws of motion and gravity.

How would you place two electrons on a sphere of radius r so that the electrostatic potential energy is minimized. how would you place three electrons to solve the same problem.

Mass (kg) force (n) 5 25 10 50 15 75 20 100 a student was trying to find the relationship between mass and force. he placed four different masses on a table and pulled them using a spring scale. the table shows the different masses used in the experiment and the force required to pull each mass. the student concluded that more force was required to pull heavier objects. what comment would you make regarding his conclusion? a) no clear relation can be observed between mass and force from the data. b) there is a direct proportion between the mass and force listed in the table. c) gravity should have been taken into account while performing the experiment. d) there is an inverse proportion between the mass and force listed in the table.

Waves that cause the most damage during an earthquake are a. surface waves c. s waves b. p waves d. ocean waves