DCA Review: Speed, Velocity,Acceleration and graphs

DCA Review: Speed, Velocity,Acceleration and graphs

Test is on Dec. 13 and 15

Describing Motion

• There are 3 words that we use to describe motion

• Speed, Velocity and Acceleration

Speed

• What is speed?

• How do we describe the speed of objects?

Speed

• Speed is how fast an object is moving

• We use terms like miles per hour, meters per seconds. (mph and m/s)

Velocity

• What is velocity?

• What is an example of velocity?

Velocity

• Velocity is speed with direction.

• An example of velocity is: A dog runs 5 m/s going left.

• The speed of the dog is 5m/s and the direction of the dog is "left".

Acceleration

• What is acceleration?

• Give an example of acceleration.

• 
  

Acceleration

• Acceleration is: speed up, slow down, or change direction.

• Example of acceleration: A car is driving 50 mi/hr and begins to drive at 60 mi/hr.

• Example of acceleration: A car is driving straight and then makes a right turn.

Multiple Select

Which of the following are examples of speed?

• Boat sails 60 knots/hour

• Plane flies 2000km/min

• Car starts at 50 mi/hr and begins to drive at 80 mi/hr

• MrC is sitting down on the chair and then begins to walk.

Multiple Choice

Which sentence describes velocity?

• Speed with distance

• Speed with direction

• Speed up

• Slow down

Calculating Speed

• To calculate speed you divide the distance by time.

• Speed= distance/time

• Units of time are usually: m/s, km/s, km/hr, m/min.

Multiple Choice

Reese can run 10 meters in 5 seconds. What is her speed?

• 5 meters/sec

• 2 meters/sec

• 5 miles/hour

• 2 miles/hour

Multiple Choice

What is the formula to calculate speed?

• S = t/d

• S = d/t

• S = d x t

• S = t x d

Motion Graphs

• There are two types of motion graphs.

• Speed graphs

• Acceleration graphs

Speed Graph

This graph has distance on the Y-axis. You will use terms like Constant Motion, Not Moving, and Constant Motion going back in this type of graph.

Acceleration Graph

This graph has Speed on the Y-axis. You will use terms like Speed Up, Constant Motion, and Slow Down in this type of graph.

Multiple Choice

How far did they run?

• A)100 seconds  

• B)100 meters

• C)18 meters 

• D)18 seconds

Multiple Choice

What is the speed of this object at 3 seconds?

• 5 m/s

• 45 m/s

• 5 s/m

• 45 s/m

Multiple Choice

How fast is the object traveling between points B and C?

• 1 km/hr
• 0 km/hr
• There is no way to tell from this graph
• 0.9 km/hr

Multiple Choice

How many times does this object STOP moving?

• None

• Once

• Twice

• Three times

Multiple Choice

What is this graph showing?

• Constant Speed

• Acceleration (speeding up)

• Deceleration (slowing down)

• No motion