MIDTERM

Question 1

What is the language of science?

Answer 1

mathematics

Question 2

What is the scientific method?

Answer 2

1) Recognize a question or a puzzle- such as an unexplained fact
2) Make an educated guess- A hypothesis
3) Predict consequences to the hypothesis
4) Perform experiments or make calculations to test the predictions.
5) Formulate the simplest general rule that organizes the three main ingredients: Hypothesis, Predict effects, and experimental findings.

Question 3

What is a fact?

Answer 3

A close agreement by competent observers who make a series of observations about the same phenomena.

Question 4

What is a law?

Answer 4

When a hypothesis has been tested over and over agian and has not been contradicted, it may become law or principle.

Question 5

what is a theory?

Answer 5

A synthesis of a large body of a large body of information that encompasses well tested and varified hypothosis about surtain aspects of the regular world.

Question 6

What is inertia?

Answer 6

the property of an object to resist change in motion.

Question 7

What is Newton’s first law?

Answer 7

Every object continues in a state of rest or of uniform speed in a straight line unless acted on by a nonzero net force.

Question 8

What is a force?

Answer 8

A push or a pull

Question 9

What is a NET FORCE?

Answer 9

When more than one force is acting on an object.

Question 10

What is a vector?

Answer 10

An arrow drawn to scale used to represent a vector quantity.

Question 11

What is a vector quantity?

Answer 11

A quanity that has both magnitude and direction, such as force.

Question 12

Scalar quantity?

Answer 12

A quantity that has magnitude but not direction, such as volume.

Question 13

Resultant?

Answer 13

The net result of a combination of two or more vectors.

Question 14

Mechanical equilibrium?

Answer 14

the state of an object or system of objects for which there are no changes in motion. in accord with newtons first law, if an object is at rest, the state of rest persist. If an object is moving, its motion continues without change.

Question 15

Equilibrium rule?

Answer 15

For any object or system of objects in equilibrium, the sum of the forces acting equals zero. in the equation form EF=0

Question 16

Speed?

Answer 16

How fast an object moves; the distance traveled per unit of time.

Question 17

Instantaneous speed?

Answer 17

The speed at any instant

Question 18

Average speed?

Answer 18

the total distance traveled divided by the time of travel

Question 19

Velocity?

Answer 19

An object’s speed and direction of motion

Question 20

Vector quantity?

Answer 20

A quantity that has both magnitude and direction

Question 21

Scalar quantity?

Answer 21

A quantity that has only a magnitude, not a direction

Question 22

Acceleration?

Answer 22

The rate at which velocity changes with time; the change in velocity may be in magnitude, or direction, or both.

Question 23

Free fall

Answer 23

Motion under the influence of gravity only.

Question 24

Friction

Answer 24

The resistive force that opposes the motion or attempted motion of an object either past another object with which it is in contact or through a fluid.

Question 25

Mass

Answer 25

The quantity of matter in an object. More specifically, it is the measure of the inertia or sluggishness that an object exhibits in response to any effort made to start it, stop it, deflect it, or change in any way its state of motion.

Question 26

Weight

Answer 26

the force upon an object due to gravity, mg.

Question 27

Kilogram

Answer 27

the fundamental SI unit of mass.

Question 28

Newton

Answer 28

The SI unit of force.

Question 29

Volume

Answer 29

The quantity of space an object occupies

Question 30

Newtons second law.

Answer 30

The acceleration of an object is directly proportional to the net force acting on the object, is in the direction of the net force, and is inversely proportional to the mass of the object.

Question 31

Terminal speed

Answer 31

the speed at which the acceleration of a falling object terminates because air resistance balances the gravitational force

Question 32

Terminal velocity

Answer 32

The terminal speed with direction specified

Question 33

Newtons third law

Answer 33

Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.

Question 34

Components

Answer 34

Mutually perpendicular vectors, usually horizontal and vertical, whose vector sum is a given vector.

Question 35

Momentum

Answer 35

The product of the mass of an object and its velocity

Question 36

Impulse

Answer 36

The product of the force acting on an object and the time during which it acts.

Question 37

Impulse- momentum relationship

Answer 37

Impulse is equal to the change in the momentum of the object that the impulse acts upon. in symbolic notation Ft= triangle mv

Question 38

Law of conservation of momentum

Answer 38

in the absence of an external force, the momentum of a system remains unchanged. Hence, the momentum before an event involving only internal forces is equal to the momentum after the event

Question 39

Elastic collision

Answer 39

A collision in which objects rebound without lasting deformation or the generation of heat.

Question 40

inelastic collision

Answer 40

A collision in which objects become distorted, generate heat, and possibly stick together.

Question 41

Work

Answer 41

The product of the force and the distance moved by the force. W= Fd

Question 42

Power

Answer 42

the time rate of work. Power= work done/ time interval

Question 43

Energy

Answer 43

The property of a system the enables it to do work.

Question 44

Mechanical energy

Answer 44

Energy due to the position of something of the movement of something

Question 45

Potential energy

Answer 45

Energy that something possesses because of its position

Question 46

Kinetic energy

Answer 46

Energy that something possesses because of its motion. Kinetic energy = 1/2 mv^2

Question 47

Work- energy theorem

Answer 47

the work done on an object equals the change in the kinetic energy of an object.

Question 48

Efficiency

Answer 48

the percentage of work put into a machine that is converted into useful work output.