ReviewSignificant Figures, Vector MathVelocity, Acceleration, Force

A Scientific Method

Accuracy and Precision

Accuracy – How close to the actual value

Precision – How close to each other.

A measurement of 4cm 1cm is the same as 3cm to 5cm

Significant Figures Multiplication vs. Addition Each group take one of each

measuring device (ruler, paper, and paper clip). Measure three objects and sum the results. Discuss the accuracy of your results. Explain how the measurement with the least significant figures affects your final result.

Significant Figures Multiplication vs. Addition Addition

43.8 +5.67 49.4

Multiplication 43.8 x5.67 248.

Variables

Dependant – subject of the experiment Independent – The controlled variable

E.G. How does speed of a sail boat change with wind? The speed of the sail boat is dependent on

the wind. The wind is independent of the speed of

the sail boat.

Conversions

3Km ___m

hr ___s

1000m

1Km

1hr

60 min

1 min

60 sec

Conversions A mass of 300

grams is accelerated at a rate of 1km per minute. (F=ma)

g300g km ___kg m

Minute^2 ___s^2

2A Newton is a

kg m

s

g

g1Kg

1000g

(1 min)^2

(60 secs)^2

1000 m

1 Km

Distance vs. Displacement Distance is the sum of the segments of

the path, regardless of direction.

Displacement is the straight-line distance from the point of origin to the ending point.

Make a graph. Draw a line over to 3x and another line up to 4y. Determine the displacement and the distance.

Vector vs. Scalar

Scalar has magnitude 4 seconds

Vector has magnitude and direction 5m/s East

Relationships

Directly Proportional Graph x=2y

Inversely Proportional x=1/2y

Exponentially Proportional x=y^2

Average Velocity

The slope on a position-time graph is velocity (displacement divided by time).

Position vs. Time

Average Acceleration

Average acceleration is the slope on a velocity-time graph.

Velocity vs. Time

vslope

t

va

t

Position, Velocity, and Acceleration

dslope

t

vslope

t

Horizontal and VerticalComponents of Motion

Solve for delta y in terms of the vertical components of vf and vi

Solve for t in terms of the vertical components of delta y, and v

2

2 2

1 where or height

2

2

f i

i f i

f i

v v at

y v t at y d d

v v a y

y

t

Equations with respect to the vertical component (y):

Horizontal and VerticalComponents of Motion Virtual Lab

Cannon Exercise Juggling Exercise

Horizontal and Vertical Projectiles

Force

www.HowStuffWorks.com “How Force, Power, Torque, and Energy

Work”

Forces on an Object

Tension

FrictionFeetFriction Sled

Newton’s First Law

A body continues to maintain its state of rest or of uniform motion unless acted upon by an external unbalanced force.

Motion and Newton’s Second Law

Force equals mass times acceleration

Net Force

Net force is the force associated with acceleration (F=ma).

Net force is the sum of all forces acting on a system.

If the forces acting on a system do not cancel each other (add to a non-zero result, that is, are not in equilibrium), the system undergoes acceleration in the direction of said force.

Note: Equilibrium means that there is a net force of zero (no acceleration).

Weight and Normal Force

Forces on an Inclined Plane

Forces on an Inclined Plane

Newton’s Third Law: Interaction Pairs

To every action there is an equal and opposite reaction.

Vector Components

Vector Components

Forces on an Inclined Plane

Surface and Friction

Static Friction

Trajectory of a Projectile

Horizontal and VerticalComponents of Motion Which component directly determines

time in the air? Which component directly determines

distance traveled

Relative Velocity

Relative Velocity

Angular Velocity

How fast an angle is traversed.

Circular Motion

Angular Velocity

Circumference Period Frequency Centripetal Acceleration

Centripetal Force A centripetal force is not a new type of

force; rather, it describes a role that is played by one or more forces in the situation, since there must be some force that is changing the velocity of the object. For example, the force of gravity keeps the Moon in a roughly circular orbit around the Earth, while the normal force of the road and the force of friction combine to keep a car in circular motion around a banked curve.

Angular Acceleration

Car Experiment – Virtual Lab Merry-go-round Experiment – Virtual

Lab