Let's Talk Forces & Motion
Students learn about forces that act on an object, specifically the forces that cause an object to move, and build their own catapult and balancing robot.
This workshop includes fundamental lessons to introduce the topic of forces that act on an object, specifically the forces that cause an object to move. It includes discussions of push and pull forces, stored energy, kinetic energy and gravity. Students have the opportunity to apply the concepts learned into building their own catapult and balancing robot.
This virtual outreach activity is split into a pre-activity document - i.e., workshop overview and list of materials with preparation instructions for both the volunteer and educator, a post-activity document - i.e., extra information and resources for the educator after the activity, and a PowerPoint presentation with presenter notes to help lead the workshop virtually.
What You Need
Activity 1: Build a Catapult
Select 1 of the 3 options based on the materials that are available to you. You DO NOT need to have materials for all 3 options.
- Option 1:
- Popsicle sticks (x10)
- Rubber bands (x3)
- Optional: Plastic Spoon (1)
- Option 2:
- Cylinder object (i.e. ribbon roll, toilet paper roll, water bottle, etc.)
- Plastic spoon (x1)
- Rubber Bands (x3)
- Option 3:
- Plastic cup
- Balloon
- Scissors
- You will also need projectiles (i.e. Marshmallows, pom poms, etc.)
Activity 2: Balancing Robot
- Balancing Robot Template printed on cardstock (x2) - You can also print it on normal paper and cut it out on cardboard or bristol board
- Dimes (x2) - Small buttons, beads or pennies can work as well
- Scissors
PowerPoint:
Pre-Activity Attachment:
Safety Notes
Ensure you are familiar with Let's Talk Science's precautions with respect to safe delivery of virtual outreach to youth. These precautions can be found in the manual for this activity.
What To Do
Pre-Activity Prep:
Students must complete the following PRIOR to the workshop.
- Print out the following sheets (total of 2 sheets):
- Balancing Robot Template (x2)
- Print on cardstock
- If cardstock is unavailable, print on normal paper and cut the shape on cardboard or bristol board.
- Balancing Robot Template (x2)
- Cut out the following template:
- Balancing Robot Template
Activity 1: Building a Catapult
Option 1:
- Stack 8 popsicle sticks on top of each other.
- Secure the stack with a rubber band on either side.
- Push one popsicle stick between the two bottom popsicle sticks of the stack.
- Place one more popsicle stick on top of the stack to form a triangular shape.
- Secure the two popsicle sticks together with a rubber band.
- If you have a plastic spoon, you can attach it to the top of the popsicle stick and secure it with a rubber band to hold your objects.
Option 2:
- Place your plastic spoon on top of the cylinder object.
- Wrap an elastic band around the spoon and cylinder to secure in place.
- Wrap around another elastic band to form a criss-cross pattern with the bands.
Option 3:
- Cut the bottom of your cup.
- Cut your balloon 1/3 of the way from the closed end.
- Knot your balloon.
- Use the balloon to seal one of the open ends of the cup.
- Seal edges with tape if needed.
- Place object inside and launch!
Activity 2: Balancing Robot
- Cut out 2 robots. (Students can colour their robots if time allows. We are going to try to balance the robot with the dimes in various positions - see diagrams)
- Place the dimes in the positions indicated by the red dots on the robot examples in the slides.
- Place the other robot on top of the first using folded tape or sticky tack. The dimes/pennies/buttons should be sandwiched between two robot templates, NOT on the surface.
- Place the dime on your finger to see if it balances. Try out the different dime positions according to the slides.
Discovery
Activity 1: Building a Catapult
When we push down the catapult lever, we build up energy - creating “stored” energy.
When we let go of the lever, the “stored energy” transforms into “motion” energy.
Energy is not created or destroyed, only changed into different types of energy!!
Activity 2: Balancing Robot
When the dimes are in different places, the robot tends to fall – why? The weight is not evenly distributed and will topple over.
When the dimes are evenly placed on the legs or the body, the robot tends to fall - why? The weight is not evenly distributed so the robot will not balance.
The robot is perfectly balanced when we evenly place the dimes on the arms - why? The weight is evenly distributed to the base of the body. This is the object's centre of gravity!
Activity 1: Building a Catapult
If your class is keen on the catapult activity, get them to take it one step further with these options!
- Gather different objects to launch.
- Predict which objects will travel the farthest.
- Measure how far each object travels.
- You can also get creative with your catapult designs!
Extension: Let's Build a Bridge!
Using what you know about forces, you can build a bridge!
Your bridge should:
- Be able to hold a load (eg. 5 spoons)
- Be at least 25 cm tall.
- Be free standing.
Materials you can use:
- Craft sticks
- Paper
- Cardstock
- String
- Tape
- Scissors
- Glue
- Tape
What's Happening?
Activity 1: Building a Catapult
When we push down the catapult lever, we build up energy - creating “stored” energy.
When we let go of the lever, the “stored energy” transforms into “motion” energy.
Energy is not created or destroyed, only changed into different types of energy!!
Activity 2: Balancing Robot
When the dimes are in different places, the robot tends to fall – why? The weight is not evenly distributed and will topple over.
When the dimes are evenly placed on the legs or the body, the robot tends to fall - why? The weight is not evenly distributed so the robot will not balance.
The robot is perfectly balanced when we evenly place the dimes on the arms - why? The weight is evenly distributed to the base of the body. This is the object's centre of gravity!
Investigate Further
Activity 1: Building a Catapult
If your class is keen on the catapult activity, get them to take it one step further with these options!
- Gather different objects to launch.
- Predict which objects will travel the farthest.
- Measure how far each object travels.
- You can also get creative with your catapult designs!
Extension: Let's Build a Bridge!
Using what you know about forces, you can build a bridge!
Your bridge should:
- Be able to hold a load (eg. 5 spoons)
- Be at least 25 cm tall.
- Be free standing.
Materials you can use:
- Craft sticks
- Paper
- Cardstock
- String
- Tape
- Scissors
- Glue
- Tape