Chapter 8

Question 1

A push or pull on an object is a ___________

Answer 1

force

Question 2

___________ is a property of a moving object that causes it to continue moving.

Answer 2

Momentum

Question 3

Movement that includes both speed and direction is ______

Answer 3

velocity

Question 4

_________ resists the motion of two surfaces in contact.

Answer 4

friction

Question 5

Friction is considered _______ if it affects moving objects.

Answer 5

kinetic

Question 6

Friction is considered ________ if it affects objects at rest.

Answer 6

static

Question 7

Three outside forces that hinder momentum are ________, __________, and ___ ____________.

Answer 7

friction, gravity, air resistance

Question 8

Objects resist a change in motion. This property is called _________.

Answer 8

inertia

Question 9

The laws of ________ explain that energy is conserved, not created or destroyed, and that entropy is shown as things wear out and energy is lost.

Answer 9

thermodynamics

Question 10

The metric unit used to measure force is called a ______.

Answer 10

newton

Question 11

The speed of a bicycle traveling north 48 mi in 4 hr is ______

Answer 11

12 mph

Question 12

The velocity of a bicycle traveling north at 48 mi in 4 hr as it returns home would be _______

Answer 12

12 mph south

Question 13

Two billiard balls collided. One was stationary. The other was moving at a velocity of 5 m/sec. The mass of the billiard ball is 0.15 kg. The momentum that was transferred to the second ball was___________

Answer 13

0.75 kgxm/sec

Question 14

Acceleration is directly related to _________.

Answer 14

force and mass

Question 15

The area of science that studies how energy is transferred from place to place and into different forms is ____.

Answer 15

thermodynamics

Question 16

Inertia is another name for Newton’s _______ law of motion.

Answer 16

first

Question 17

What is Newton’s first law?

Answer 17

Things at rest tend to stay at rest and things in motion tend to stay in motion unless acted upon by an outside force.

Question 18

What is Newton’s second law?

Answer 18

Force is the mass of an object multiplied by its acceleration.

Question 19

What is Newton’s third law?

Answer 19

For every action there is an equal and opposite reaction.

Question 20

Identify which of Newton’s three laws is most at work:

Two billiard balls collide and move in opposite directions.

Answer 20

Newton’s Third law

Question 21

Identify which of Newton’s three laws is most at work:

A car continues moving until the driver brakes suddenly.

Answer 21

Newton’s First law

Question 22

Identify which of Newton’s three laws is most at work:

A student can throw a baseball faster than he can throw a basketball.

Answer 22

Newton’s Second law

Question 23

What are the challenges related to creating a perpetual motion machine?

Answer 23

Friction, air resistance, and gravity all pose challenges to creating a perpetual motion machine. As the machine moves, energy is lost. The conversion of energy is never 100%

Question 24

looking at an image of a person surfing on a wave:

1. describe forces opposing motion.
2. label and describe the static and kinetic forces

Answer 24

The types of motion in evidence are the surfer moving to balance, the waves moving, the board moving with the waves, and wind. Friction and air resistance are opposing motion. There is static friction where the surfer’s feet are touching the board, and kinetic friction between the board and the waves.