Projectile Lab

9/30/13

Objective:

• To determine effect on projectiles if we include air resistance

Pre-Lab: (answer in complete sentences)

1. What angle do you think will launch an object the furthest?

2. How much of a roll do you think air resistance has on a fast moving object?

3. What do you think will happen to the range of an object as you increase the angle?

4. What do you think will happen to the hang time of an object as you increase the angle?

Procedures:1. Using the PhET computer simulation,

launch an object at 45 m/s at a 5° angle without air resistance

2. Record the range and hang time

3. Increase the angle by 5° and repeat step 1 until you get to 85°

4. Repeat steps 1-3 but add air resistance

Data Table: Projectile AnglesAngle (°) Range-No

Air (m)Time-No Air (s)

Range-With Air (m)

Time-With Air (s)

5        

10        

15        

20        

25        

30        

35        

40        

45        

50        

55        

60        

65        

70        

75        

80        

85        

Projectile Lab (day 2)

10/1/13

Data Table: Projectile Angles (part 1)

Settings:

• velocity = 45.0 m/s

• mass = 70.0 kg

• diameter (size) = 1.0 m

Pre-Lab: Part 2 and 3

Including air resistance:• What do you think will happen to

the range of an object as you increase the mass?

• What do you think will happen to the range of an object as you increase the size?

Data Table: Projectile Mass (part 2)Settings:• angle = 45.0°• velocity = 45.0 m/s• diameter (size) = 1.00 m

Mass (kg) Range-With Air (m) Time-With Air (s)

20.0    

40.0    

60.0    

80.0    

100.0    

120.0    

Data Table: Projectile Size (part 3)Settings:• angle = 45.0°• velocity = 45.0 m/s• mass = 70.0 kg

Diameter / Size (m) Range-With Air (m) Time-With Air (s)

0.40    

0.60    

0.80    

1.00    

1.20    

1.40    

Graphs: (You will have two graphs total.)

• Use the whole graph with an appropriate scale

• Include titles and units

• Graph 1: Make a graph with angle on the x-axis and range on the y-axis.

• Graph 2: Make a graph with angle on the x-axis and time on the y-axis.

• *** Plot the data with and without air resistance on the same graph ***

• Identify ALL variables in the lab as independent, dependent or controlled for each part 1, 2, & 3

• Using your data from the tables explain what happen to the object if we include air resistance

• Explain your graphs.– What are the shapes and slopes of the graphs?– What are the trends?– Compare your graphs to the ones on pages 35

and 37 in the textbook• How do the factors effect an object’s motion if we

include air resistance? (i.e. If you increase one quantity what happens to the other quantity?)

• What can we do to objects to reduce the effect of air resistance?

Conclusion: (10 sentence min. in paragraph form)

Bellwork (10/1/13)

• What is air resistance?

• A force of friction that acts on an object moving through the air

Announcements

• Grades are up to date except for the Linear Motion Tests

• Any absent work needs to be made up by Friday 10/4/13 for the progress report

• Before school 7:00-8:00 am; Conference periods (Wed. and Thurs.); also Thursday after school