Machines in MotionWhat makes a machine move? A force does.

Problem:

Part 1) How does the amount of force affect the speed?Part 2) How does the mass of the car affect the speed?

Variables: Part 1:Independent: __________Dependent: ___________

Part 2:Independent: __________Dependent: ____________

Materials:• meter stick• Newton scale• Trolley and “launching ramp”• Strong rubber band

2 N

2 N

HYPOTHESES• PART 1: How does the amount of force

affect the speed?– If the ____(IV)_____ is increased,– Then the __(DV)__ will _(choose one)_

– Because __(use sci knowledge to explain)__

• PART 2:How does the mass of the car affect the speed? – Follow the same format as above

2 N

2 N

PROCEDURE:•Pull back the rubber band to 2N and launch the car.•Mark the distance with a piece of tape (this is your “finish line”).•Measure and record this as your distance in your data table.•Now pull the rubber band back to the 2N mark and launch the car again. • Measure the time it takes the car to reach the finish line and record it in the table. Repeat this 2 more times for a total of 3 trials. •Repeat steps #4 & #5 for 4N, 6N, and 8N. •Repeat the whole lab again with a heavier car.

Finish line

Data: How does Force affect speed? Mass of car 1_____________g Force (N) Trial

Number Time (sec)

Average time (sec)

Distance (cm)

Speed (cm/sec)

1 2

3

1 2

3

1 2

3

1 2

3

Data 2: How does increasing the mass affect the speed? Repeat the experiment with a heavier car. Mass of car 2__________________ g Force (N) Trial

Number Time (sec)

Average time (sec)

Distance (cm)

Speed (cm/sec)

1 2

3

1 2

3

1 2

3

1 2

3

Graphing Results

Graphing Draw a graph of your results for both labs. Use the axis below as a guide. You need to plot the Force against the average speed. Draw the line of best fit for each of the cars. Make sure you label the axis and the lines, include a title underlined. Units must be used. Speed (m/s) Car 2 Car 1 Force (N)

The Relationship Between _both IV’s__ and the_DV_

units

units

(Heavy)

(Light)

Conclusion/Summary:

• Is your hypothesis for PART 1 right or wrong? Explain.

-Restate your hypothesis

-State whether right or wrong

-Use data (#’s) to support why hypothesis is right or wrong

2. Is your hypothesis for PART 2 right or wrong? Explain. (follow same steps as above)

3. Identify Sources of Error AND how to improve them.