Instructional Objectives : 1.Research on motion and force2. Research using virtual investigations

Homework:Monday- Notes 79-81 Ch.11)Vocabulary Tuesday- Notes 82-83 Study VocabularyWednesday- Speed and velocity worksheetThursday- Speed, Velocity, and acceleration worksheet

Motion:process of changing place

• Distance: how far something has moved (This does not deal with direction!!!)

• Displacement: how far something has moved in a DIRECTION

Think about the motion of a roller coaster car.

• The length of the path along which the car has traveled is distance.

• Displacement is the direction from the starting point to the car and the length of the straight line between them.

• After completing a trip around the track, the car’s displacement is zero.

Measuring Displacements

A. Add the magnitudes of two displacement vectors that have the same direction.

B. Two displacement vectors with opposite directions are subtracted from each other.

Combining Displacements

Location

• Position: an object’s location• Reference Point: a known

position used to locate something

Ex: - The car is next to the blue truck.

Rate

• A rate is how often something happens.

Ex: 4 meters every second or 12 drops every minute.

• the rate that something changes its position

• Ex: 50 miles per hour

Two types of speed

• Instantaneous speed: the rate of motion at a given instant in time (happens right now).

• Constant speed: unchanging speed

Average speed

• the total distance traveled divide by the total time

• is what we can calculate.

Scaler and Vector

• Scaler : a measurement that has no specific direction

• Vector : a measurement having a specific direction

Calculating Speed

• Speed = Total Distance . Total Time

• Speed Units are: • miles/hour, • meters/second, • feet/minute, and other such units.

Instructional Objectives : 1.Learn the difference between positive and negative accelerations2. Learn the difference between speed and velocity

Speed Problem #1

• A truck travels 40 Km. in 20 minutes. Find its speed.

• Solution: Speed = 40 Km. . 20 min. Speed = 2 Km./min.

Speed Problem #2

• An airplane is traveling at 200 miles/hr. for 5 hours. How far does it travel?

• Solution:200 m/hr = Distance (Dist.= Speed x T.) 5 hr. Distance = 1000 miles

Speed Problem #3

• How long does it take a boy to run 500 meters at 5 m/sec?

• Solution: 5 m/s = 500 m . Time (Time x 5 m/sec = 500 m) Time = 100 seconds

Velocity 1

• Velocity: speed in a certain direction

• (Velocity ALWAYS has a DIRECTION !!!!!!)

• Ex: 5 miles/hr East or 20 meters/sec downward.

Velocity 2

• Velocity MUST ALWAYS show a DIRECTION!!!!!!!!

If it does not show a direction, you have reported

a SPEED!!!!!!!!!!!

Velocity Problem #1

• A turtle crawls 200 meters North in 20 minutes. Find its velocity.

• Solution: Speed = 200 meters (Add direction) 20 mins. Velocity = 10 m/min. North

Speed Graphs 1

• Distance on Y-axis & Time on X-axis.

• Slope of line is Speed!

Speed Graphs 2

• Slope of Red Line is 2400 - 0 m. 30 - 0 min. Or 80 m/min (this is speed)

Instructional Objectives : 1.Identify positive and negative accelerations2. Learn the difference between speed and velocity

What is Acceleration? Change in Speed-Ex: negative acceleration and positive accelerationConstant speed means zero acceleration

Change in direction -car traveling in a circle

Change in Speed and direction -Ex: Roller coaster

Constant Acceleration -Steady change in velocity

What is ?

• Acceleration: the rate of change in velocity

• Positive Acceleration is a Gain in speed.

• Negative Acceleration is a Loss in speed.

• Use the following formula: acceleration=velocity change . time or a = vf - vi . t

• Acceleration Units: m/sec2, miles/hour/sec., yards/min.2, or such as this

Positive Acceleration

is when velocity increases.

Negative Acceleration

• is when velocity decreases.

• Always subtract velocities first then divide by the time.

Acceleration Problem #1a

• A motorcycle accelerates from 20 miles/hr to

80miles/hr in 6 seconds. What is its rate of

acceleration?

Answer to Problem #1a

• Acc. = Vf - Vi = 80 - 20 m/h . t 6 sec Acc. = 60 m/h = 10 m/h/sec . 6 sec acceleration . is positive.

Acceleration Problem #2a

• A car slams on brakes when traveling at 200 meters/sec and stops in 10 seconds. What was the car’s rate of acceleration?

Answer to Problem #2

• Acc. = Vf - Vi = 0 -200 m/sec . t 10 sec Acc=- 200 m/sec = -20m/s/s . 10 sec or -20 m/s2 .

(Acceleration is negative.)