Which of the following answers describes kepler's laws?
a. planets orbit in elliptical patterns; the bigger the planet, the more gravitational pull; a planet's gravitational pull is stronger or weaker depending on its distance from the sun.
b. a planet's orbit covers equal distances in equal amounts of time; the speed of a planet's orbit depends on its distance from the sun; the bigger the planet, the slower it moves.
c. planets orbit in elliptical patterns; a planet's orbit covers equal areas in equal amounts of time; planets' orbits are shorter or longer depending on their distance from the sun.

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.

Suppose that 27 j of work is needed to stretch a spring from its natural length of 6 m to a length of 9 m. (a) how much work is needed to stretch the spring from 12 m to 14 m? j (b) how far beyond its natural length will a force of 78 n keep the spring stretched?

Which one of the following terms is used to indicate the natural tendency of an object to remain at rest or in motion at a constant speed along a straight line? velocity acceleration equilibrium force inertia