Chapter 8 Flashcards
A push or pull on an object is a ___________
force
___________ is a property of a moving object that causes it to continue moving.
Momentum
Movement that includes both speed and direction is ______
velocity
_________ resists the motion of two surfaces in contact.
friction
Friction is considered _______ if it affects moving objects.
kinetic
Friction is considered ________ if it affects objects at rest.
static
Three outside forces that hinder momentum are ________, __________, and ___ ____________.
friction, gravity, air resistance
Objects resist a change in motion. This property is called _________.
inertia
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.
thermodynamics
The metric unit used to measure force is called a ______.
newton
The speed of a bicycle traveling north 48 mi in 4 hr is ______
12 mph
The velocity of a bicycle traveling north at 48 mi in 4 hr as it returns home would be _______
12 mph south
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___________
0.75 kgxm/sec
Acceleration is directly related to _________.
force and mass
The area of science that studies how energy is transferred from place to place and into different forms is ____.
thermodynamics
Inertia is another name for Newton’s _______ law of motion.
first
What is Newton’s first law?
Things at rest tend to stay at rest and things in motion tend to stay in motion unless acted upon by an outside force.
What is Newton’s second law?
Force is the mass of an object multiplied by its acceleration.
What is Newton’s third law?
For every action there is an equal and opposite reaction.
Identify which of Newton’s three laws is most at work:
Two billiard balls collide and move in opposite directions.
Newton’s Third law
Identify which of Newton’s three laws is most at work:
A car continues moving until the driver brakes suddenly.
Newton’s First law
Identify which of Newton’s three laws is most at work:
A student can throw a baseball faster than he can throw a basketball.
Newton’s Second law
What are the challenges related to creating a perpetual motion machine?
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%
looking at an image of a person surfing on a wave:
- describe forces opposing motion.
- label and describe the static and kinetic forces
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.
