## UFOs

### Cathie LondonSanta Rosa District Schools

#### Description

Watch out for flying objects! The lesson employs the construction and utilization of a catapult to understand that motion is determined by the effect of forces on an object.

#### Objectives

The student knows that the motion of an object is determined by the overall effect of all of the forces acting on the object.

#### Materials

-Picture of catapult
-Small, narrow, rectangular blocks of wood, one for each group and each block the same size
-Plastic spoons of varying lengths
-Large or small marshmallows
-Rulers
-Metric sticks of tape measures; one for each group
-Pencils
-Checklist/catapult instructions (see associated file)
-Data worksheet (see associated file)

#### Preparations

1. Gather and separate materials for activity.
2. Preplan spoon lengths for each group.
3. Make copies of checklist/catapult instructions and data worksheet for each student (see associated file).
4. Assign students into working groups of four to five per group.
5. Designate working space for each group.

#### Procedures

NOTE: This lesson is a discovery activity done before the study of force and motion.
NOTE: Quickly review how to measure using a meter stick or tape measure.

1. Ask students if they have ever thrown a ball to someone.

2. Demonstrate by throwing a ball to different students at varying distances.

3. Ask what you do to throw the ball further.

4. Hold up a picture of a catapult used in Roman times.

5. Ask how and why the catapult may have been used.

6. Distribute and, using the data worksheet, go over instructions for making a catapult and how the student uses the data worksheet. (see associated file)

7. Assign the students into working groups of four to five students per group and distribute supplies to each group. Send each group to a firing station.

8. Each group will then construct one catapult. Once a catapult is completed and each student has completed the checklist, the teacher checks the checklist.

9. After given the go ahead by the teacher, the students will place the catapult on the floor, put a marshmallow into the cup of the spoon and “fire away”.

10. The students predict, then measure and record the measured distance on his/her data worksheet (see associate file).

11. Leaving the catapult and marshmallows at the station, students move to the next station, and repeat steps 9 and 10. Spoon lengths vary from station to station imploring new predictions. Students continue doing this until each group has been to each firing station.

12. Call the students back from their groups. Go over the data worksheet orally with each group, recording the data on the chalkboard. After each group has given their data, prompt responses by asking questions and encouraging observations.

#### Assessments

The student demonstrates his/her understanding of the effects of force on motion of an object through the design and use of a catapult. Students are formatively assessed using a checklist and data worksheet (see attached file).

#### Extensions

The students make a bar graph showing the outcomes of the activity.

#### Attached Files

A checklist / instructions for the catapult used for assessment.     File Extension: pdf

A data worksheet used as a student response sheet.     File Extension: pdf