Conceptual Physics (Exam 1)

Question 1

In what ways do we express motion?

Answer 1

a. Mathematical: speed=d/t velocity = D/t
Acceleration: v/t
b. Graphing
c. Dots

Question 2

Scalars

Answer 2

measurements that only use a magnitude

Question 3

Example of Scalars

Answer 3

Speed, Time, Distance

Question 4

Vectors

Answer 4

measurements that need a magnitude and direction

Question 5

Example of Vectors

Answer 5

Velocity, Acceleration, Displacement, Force, Momentum

Question 6

Newton

Answer 6

1. Optics: white light is a combo of all the colors of the rainbow.
2. Calculus: developed differentiation and integration
3. Gravity + Motion:
4. Law of Intertia
5. Law of Acceleration
6. Law of Action + Reaction (F= ma)

Question 7

Einstein

Answer 7

1. Light travels in waves that radiate outward from the source of light.
2. Light is a constant speed, you can’t speed it up or slow it down.
3. Scientists of the day believed the speed of light should be affected by how fast the source of light was moving through the ether.
   Ex: Light from a source moving toward you, such as a train, would travel faster than light from a stationary source like a signal light.

Question 8

Aristotle

Answer 8

3 Laws of Motion
1. Objects fall at a constant rate. (depending on size and weight)
2. Violent vs. natural motion (pushing and pulling objects)
3. Objects in the heavens move in circular motions without external force. Objects on earth move in straight lines unless forced into circular motions.

Question 9

Kepler

Answer 9

Three Laws of Planetary Motion
1. planets move in elliptical paths around the sun.
2. when planets are closer to the son, they orbit faster.
3. it takes longer to orbit the sun when further away.

Question 10

Galileo

Answer 10

• Discovery of momentum with ramp experiment.
• Acceleration = 9.8 m/s
  discovered acceleration can be speeding up, slowing down, or changing directions.
  discovered that if you drop a ball down a ramp, the speed will increase, but the acceleration will be constant.
• Studied Aristotle’s “natural + violent” motions.
• Furthered/corrected Aristotle’s ideas

Question 11

Newton’s First Law of Motion

Answer 11

An object in motion tends to stay in motion and an object at rest tends to stay at rest unless acted upon by an unbalanced force.

Question 12

Example of Newton’s First Law of Motion

Answer 12

A ball rolling down a hill won’t stop rolling until friction or another force stops it.

Question 13

Newton’s Second Law of Motion

Answer 13

Force equals mass times acceleration

Question 14

Example of Newton’s Second Law of Motion

Answer 14

Riding your bicycle. Bicycle is the mass, leg muscles pushing on the pedals of your bicycle is the force.

Question 15

Newton’s Third Law of Motion

Answer 15

For every action, there is an equal and opposite reaction.

Question 16

Example of Newton’s Third Law of Motion

Answer 16

A book lying on a table: The weight of the books is acting in the downward direction on the table (action). While the reaction acts in the upward direction on the books.

Question 17

What is force?

Answer 17

Force is a push or pull that has size and direction.

Question 18

How do we measure forces?

Answer 18

Newtons

Question 19

Types of Forces:

Answer 19

1. Applied Force
2. Air Resistance
3. Gravity
4. Friction
5. Spring Force (compression/tension)
6. Normal Force
7. Electrical Force
8. Magnetic Force
9. Buoyancy

Question 20

Air Resistance Force

Answer 20

Friction between an object and the air

Question 21

Applied Force?

Answer 21

Applied force is when a living creature puts pressure on a object.

Question 22

Spring Force?

Answer 22

When an object is pushed together, then when pressure is taken away it pops back to its normal self
Compression/Tension

Question 23

Frictional Force?

Answer 23

Frictional forces is present everywhere in our daily life. It is simply impossible to reduce it completely.

Question 24

Electrical Force?

Answer 24

The attractive or repulsive interaction between any two charged objects.

Question 25

Normal Force?

Answer 25

the support force exerted upon an object which is in contact with another stable object.

Question 26

Magnetic Force?

Answer 26

Same as gravitational and electrical forces in that no one knows what it is. It is different from these forces in that its potential and momentic energy are at the expense of an electrical field in time.

Question 27

Unbalanced Force

Answer 27

can cause an object to move, stop moving, or change

Question 28

Balanced Force

Answer 28

Forces in equal and opposite directions; no acceleration

Question 29

4 Types of Friction

Answer 29

1. Sliding Friction (strongest) 2. Rolling Friction 3. Fluid Friction (weakest/liquid/gas) 4. Static Friction

Question 30

What is gravity?

Answer 30

a force of gravity that pulls objects around it, more mass great gravity pull, depends on mass and distance

Question 31

How is it applied to objects?

Answer 31

As objects move closer together, their pull on each other grows stronger. As objects move farther apart, their pull on each other weakens.

Question 32

How is it applied to planets?

Answer 32

Gravity is what holds the planets in orbit around the sun and what keeps the moon in orbit around Earth.

Question 33

What does gravity depend on?

Answer 33

Depends on the mass of an object and the distance between the centers of the two objects.

Question 34

What is momentum?

Answer 34

The quantity of motion that an object has...arising from velocity and the quantity of matter conjointly. Any object which has both mass and velocity is said to have momentum.

Question 36

The Law of Conservation of Momentum?

Answer 36

The total momentum for any given system will remain constant unless acted upon by an external force... Or The momentum before a collision is equal to the momentum after a collision.

Question 37

Formula

Answer 37

p = mv momentum = mass times velocity

Question 38

Elastic Collision vs. Inelastic Collision

Answer 38

Elastic collisions are collisions in which both momentum and kinetic energy are conserved. The total system kinetic energy before the collision equals the total system kinetic energy after the collision. If total kinetic energy is not conserved, then the collision is referred to as an inelastic collision.

Question 39

How is the Law of Conservation of Momentum still present through elastic and inelastic collision?

Answer 39

Momentum is always conserved, even when there are forces if you take into account every object interacting through forces as part of your system.