unit 2

Question 1

acceleration due to gravity

Answer 1

the acceleration due to gravity at the earth’s surface – g = 9.8m/s2 or 32 ft/s2

Question 2

cenrtipetal acceleration

Answer 2

acceleration, directed toward the center of a circular path, that produces uniform circular motion

Question 3

centripetal force

Answer 3

center-pointing force

Question 4

conservation of momentum

Answer 4

the physical law that states that total momentum before an interaction is equal to the total momentum after the interaction

Question 5

copernican system

Answer 5

a heliocentric system advocated by Copernicus with planets in circular orbits around the sun

Question 6

dynamics

Answer 6

the branch of physics concerned with the causes of motion and how the nature of the object affects the motion

Question 7

force

Answer 7

a push or a pull

Question 8

geocentric system

Answer 8

the system of the planets and sun in orbit around the earth

Question 9

gravitational field

Answer 9

a region of space in which a measurable gravitational force is indicated by the force exerted on a test mass

Question 10

gravitational force

Answer 10

an attractive force due to the presence of another mass

Question 11

gravitational mass

Answer 11

the mass of an object as determined by measuring the object’s weight within a given gravitational force field;

Question 12

heliocentric system

Answer 12

the system of planets in circular orbits around the sun

Question 13

impulse

Answer 13

the product of the force on an object and the time of contact

Question 14

inrtial mass

Answer 14

the mass of an object as determined by exerting a force on an object and measuring its acceleration;

Question 15

inverse square law

Answer 15

the fact that gravitational forces vary inversely as the square of the distance of separation

Question 16

Keplers law of planetary motion

Answer 16

(I) Planets orbit the sun in elliptical orbits with the sun at one focus. (II) A line from planet to sun sweeps out equal areas in equal times. (III) The cube of the orbital radius and the square of its period of revolution are factors in a ratio that is constant for all members of an orbiting system.

Question 17

momentum

Answer 17

The product of the mass of an object and its velocity.

Question 18

newtons law of motion

Answer 18

(I) Every object continues in its state of rest or of uniform motion in a straight line, unless it is compelled to change that state by forces acting on it. (II) The acceleration of an object is directly proportional to the net force acting on the object and inversely proportional to the mass of the object. (III) Every action force is accompanied by an equal and opposite reaction force.

Question 19

ptolemaic system

Answer 19

a geocentric system advocated by Ptolemy, with the earth at the center and moon, sun, and planets orbiting in circular orbits

Question 20

weight

Answer 20

the force of gravitational attraction of the earth or any other body on an object