chapter 2 study guide

Question 1

what is the law of universal gravitation

Answer 1

every particle in the universe attracts every other particle with a force directly proportional to the product of their masses

Question 2

what is newton’s first law of motion

Answer 2

an object at rest will stay at rest, and an object in motion will stay in motion at a constant speed and in a straight line, unless acted upon by an unbalanced force (inertia)

Question 3

what is newton’s second law of motion

Answer 3

the acceleration of an object depends on the mass of the object and the amount of force applied

Question 4

what is newton’s third law of motion

Answer 4

when two objects interact, they apply forces to each other of equal magnitude and opposite direction

Question 5

what is law of conservation of momentum

Answer 5

the total momentum of an isolated system remains constant, unless an external force is applied

Question 6

be able to distinguish between balanced forces and unbalanced forces

Answer 6

balanced= 0 net force. unbalanced= net force not 0

Question 7

list examples of an unbalanced force

Answer 7

person in an elevator going up and down

Question 8

list examples of a force

Answer 8

friction, gravity

Question 9

list examples of noncontact force

Answer 9

ball falling after tossed in the air

Question 10

in a graph which illustrates the effect of distance on gravity, which label goes on the horizontal axis?

Answer 10

distance

Question 11

what force is represented when a skater slows down as she slides across the ice

Answer 11

friction

Question 12

list examples of circular motion

Answer 12

car turning a corner, yo-yo on a string in a circle, moon’s orbit around earth, earth’s orbit around sun

Question 13

identify a force or motion that is involved in the moon orbiting earth

Answer 13

acceleration towards the center of the earth

Question 14

what is the force that keeps a satellite in orbit?

Answer 14

acceleration force

Question 15

explain how a force allows a person to walk forward

Answer 15

ground pushes on the person

Question 16

a student hits a nail with a hammer. explain location of forces during collision

Answer 16

force on nail and hammer

Question 17

what is the equation for momentum?

Answer 17

p = m times v

Question 18

when is a collision elastic?

Answer 18

if objects do not stick together

Question 19

what is the difference between fluid friction, static friction, and sliding friction

Answer 19

static-prevents objects from slipping when resting on a surface. sliding-occurs when an object slides over another object. fluid-occurs when objects move through a fluid

Question 20

what force must be overcome in order to start an object moving?

Answer 20

friction

Question 21

what is the equation for newton’s second law of motion?

Answer 21

a=f net/m or a=f/m

Question 22

what is the unit of measure of force?

Answer 22

newton

Question 23

what is happening with force when two people pull on a rope and it goes towards the first person?

Answer 23

unbalanced forces

Question 24

what happens to an object when an unbalanced force acts upon it?

Answer 24

accelerates

Question 25

planet with same gravitational acceleration but twice the mass. you weigh 700 n on earth, how much do you weigh on other planet?

Answer 25

1400 n

Question 26

which law of motion indicates a relationship among force, mass, and acceleration?

Answer 26

newton’s second law of motion

Question 27

identify the path of a ball if gravity did not affect a horizontally thrown ball

Answer 27

ball would continue horizontally

Question 28

moving train collides with same size other train that is motionless. how does final momentum compare to momentum of first car?

Answer 28

it is the same

Question 29

friend is incorrect

Answer 29

action reaction forces do not cancel each other out (or something like that)