Students will predict, observe, and compare what happens when a force is applied to an object.
Background for Teachers
Prior to teaching this lesson, 3rd Grade Science Standard III,
Objective 1 should already have been taught. Students will already
understand that push and pull are two forces. They will understand
how simple machines work. Students should also understand the Math
concepts of right angles, and angles that are greater than or less than a
right angle. See Science Standard III Previously Taught at the Elementary
CORE Academy sheet.
Students will already know the following terms: push, pull, forces,
motion, acute, obtuse, right, greater, less, simple machines, pulley,
wheel & axle, inclined plane, lever, screw, wedge.
Intended Learning Outcomes
1. Use Science Process and Thinking Skills.
2. Manifest Scientific Attitudes and Interests.
3. Understand Science Concepts and Principles.
4. Communicate Effectively Using Science Language and Reasoning.
Invitation to Learn
When the students come in from recess, have the straw, paper,
and cardboard waiting for them on their desk. Tell them to put the
paper and the cardboard next to each other on the edge of their desk
and try to blow them off. When they've had a chance to try each
one, have them set down their straws and ask them which one was
easier to blow off their desk. Ask them why. Discuss how some
kids can blow harder than others, etc.
- Construct the swinging hammer according to the directions on
the Swinging Hammer Construction Instructions sheet prior to the
- Have the students get out their journals. Pass out one Hammer
Time! Data Sheet to each student. Have them write their name
on it. It doesn't matter where, because they will be cutting
them out later to tape into their journals.
- Tell the students that you are going to explore forces and
motion further today.
- Find the place in your room on the floor that has the longest
straight shot for a ball to roll and then setup the swinging hammer
there. Carpet is best so that the ball is less likely to roll away
before the hammer hits it. If you only have tile, you can make a
tee by punching a hole in a piece of cardboard.
- Tell the students that we are going to explore different forces
first. We'll use the golf ball on each of three swings so that we
have the same weight.
- Have two student volunteers help you by each holding down
one side of the stand. This will insure that it doesn't move
during the swinging. Arrange the rest of the class around you
so that they don't obstruct the path of the ball.
- Move the hammer back about 30 ̊ to form an acute angle. Place
the golf ball on the floor exactly in the center of the stand.
Ask the students what they think might happen. Tell them to record their predictions in their journals. Then, let the hammer
swing. It will hit the ball, and the resulting movement will be
relatively slow, with the golf ball traveling a relatively short
distance. Use the measuring tape to measure how far the golf
ball went. Have them record it on their data sheet . Remind
them to include the units, not just the number.
- Repeat the procedure with a right angle and an obtuse (about
150 ̊) angle. Discuss the results with the students. Have them
record their observations in their journals.
- Get out the ping-pong ball and the stone sphere. This time,
use a right angle for all three swings. Repeat the procedure
three more times, using the ping-pong ball, golf ball, and stone
sphere. Be sure to discuss and record as before.
For advanced learners, find spheres of approximately the same
weight, but different material (e.g. rubber, cork, wood, clay,
etc.). They don't have to be the same size, just the same weight.
Have them use a right angle for each swing, and then observe
what happens when each sphere is struck. Have them write
down their theories as to why some balls go further than others
when they are the same weight and the same force is applied.
For advanced learners, find objects with the same weight, but
not the same shape (e.g. sphere, cone, cube, toy car, rock,
candle, etc.). Have them use a right angle for each swing, and then observe what happens when each object is struck. Have
them write down their theories as to why the objects don't
respond the same, even though they are the same weight and
the same force is applied.
For advanced learners, ask them how each of the simple
machines could be used to alter the swinging hammer. Have
them demonstrate if possible.
Make additional swinging hammers so that students can work
in small groups to conduct the activity and further explorations.
- Make additional swinging hammers that students may check out
and take home to show family members what they have learned
in school by giving a mini lesson.
- Make additional swinging hammers that students may check
out to take home. Students would experiment with their family
using different balls and then share their findings with the class.
- Have the students cut out Same Weight, Different Force and Same
Force, Different Weight from their Hammer Time! Data Sheet
paper. Students should then tape them into their journals and
record their observations in complete sentences, using correct
- As a game or center, use a flat circle (paper works fine) and
set it on the ground between one and ten feet away from the
swinging hammer (also on the floor). Then students must
choose the correct weight of ball and use the correct swinging
force to get the ball in the circle without it going past. Each
person takes a turn until someone gets it in the circle. Then,
move the circle and do it again.
MacKenzie, A. H. (2001). The role of teacher stance when infusing inquiry questioning into middle
school science classrooms. School Science and Mathematics. 101, number 3, 143-153.
This study was done to show how teacher attitude about science
affected student attitude about science. Student wonder and "not
knowing" is emphasized and valued. Science is not absolute
knowledge, but rather contextual. Students learn to synthesize their
own knowledge through exploration and experimentation. They are
required to use their imagination to solve problems and reach scientific
goals. Class discussion is important, as is student inquiry. This article
explains how to accomplish this in the classroom.
Caram, C. A., & Davis, P. B. (2005). Inviting student engagement with questioning. Kappa
Delta Pi Record. Fall, 18-23.
Questioning is important in the classroom. It taps into children's
natural curiosity. This article gives a list of strategies to use to
encourage questioning. It also has a Thinking Skills Model to give
examples of all levels of questioning, so that all learners' needs are