Name: Jakob Date:
Student Exploration: Center of Mass
Directions: Follow the instructions to go through the simulation. Respond to the questions and
prompts in the orange boxes.
Vocabulary: center of mass, mean, weighted mean
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. The head of this hammer is made of steel. The handle is made
of wood, which is much less dense than steel. Suppose you
wanted to balance the hammer on your finger. Draw an ✏️
arrow to indicate where you would balance the hammer on
your finger. (Click on the image, select
tools).
✏️
edit to open drawing
2. Explain why you chose to draw an arrow where you did:
The side center of which the steel side is heavier to make the weight of the hammerhead’s
side equal to the weight
Gizmo Warm-up
Suppose you tried to balance a hammer by placing your finger halfway
down the handle. The hammer would fall because the head is much
heavier than the rest of the hammer. Instead, you would have to place
your finger near the head to balance the hammer perfectly. The point
where an object balances is called its center of mass.
You can use the Center of Mass Gizmo to explore how changing the
distribution and masses of objects in a system affects the total system’s
center of mass. On the SIMULATION pane, drag a single block into the
white square. Turn on Show center of mass and Show mass of each
region. The center of mass is marked by a green circle.
1. Relative to the block, where is the center of mass? Is it where you
expect it to be?
The center of mass is at the center of the block, so yes.
2. Drag a second block a short distance away from the first. Where is the center of mass now?
The center of mass is between the two blocks.
Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved
, Activity A: Get the Gizmo ready:
Observing center ● Make sure two blocks are set in the large white
of mass square on the SIMULATION pane.
Goal: Observe how changing the distribution of mass in a set of objects affects the center of mass.
1. Observe: Drag one of the blocks further away from the other block and then closer together. How does this
affect the center of mass?
The center of mass when farther from each other is still in between the blocks but farther as
well, and when the blocks are closer to each other, the center of mass is closer to each block
while keeping its position in the middle.
2. Explore: Drag a third block on top of one of the first two blocks.
A. How does this affect the position of the center of mass?
The center of mass is in between all three blocks.
B. If the white area of the SIMULATION pane were a tray, where would you put your hand to pick it up?
The middle of the middle block
3. Observe: Set a third block on top of the stack of two blocks. Drag the single block close to and then away
from the stack of three blocks. Observe how the center of mass changes.
A. How did the position of the single block affect the location of the center of mass?
Depending on where the single block is positioned, the center of mass positions itself
around or inside one of the stacked blocks
B. In each case, which object was closer to the center of mass, the stack of three blocks or the single
block? The stacked three blocks
4. Apply: Suppose a heavy person and a light person sat on opposite ends of a see-saw. If they wanted the
see-saw to be balanced, which person would need to sit closer to the fulcrum (the see-saw’s pivot point)?
Explain your answer.
Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved
Student Exploration: Center of Mass
Directions: Follow the instructions to go through the simulation. Respond to the questions and
prompts in the orange boxes.
Vocabulary: center of mass, mean, weighted mean
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. The head of this hammer is made of steel. The handle is made
of wood, which is much less dense than steel. Suppose you
wanted to balance the hammer on your finger. Draw an ✏️
arrow to indicate where you would balance the hammer on
your finger. (Click on the image, select
tools).
✏️
edit to open drawing
2. Explain why you chose to draw an arrow where you did:
The side center of which the steel side is heavier to make the weight of the hammerhead’s
side equal to the weight
Gizmo Warm-up
Suppose you tried to balance a hammer by placing your finger halfway
down the handle. The hammer would fall because the head is much
heavier than the rest of the hammer. Instead, you would have to place
your finger near the head to balance the hammer perfectly. The point
where an object balances is called its center of mass.
You can use the Center of Mass Gizmo to explore how changing the
distribution and masses of objects in a system affects the total system’s
center of mass. On the SIMULATION pane, drag a single block into the
white square. Turn on Show center of mass and Show mass of each
region. The center of mass is marked by a green circle.
1. Relative to the block, where is the center of mass? Is it where you
expect it to be?
The center of mass is at the center of the block, so yes.
2. Drag a second block a short distance away from the first. Where is the center of mass now?
The center of mass is between the two blocks.
Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved
, Activity A: Get the Gizmo ready:
Observing center ● Make sure two blocks are set in the large white
of mass square on the SIMULATION pane.
Goal: Observe how changing the distribution of mass in a set of objects affects the center of mass.
1. Observe: Drag one of the blocks further away from the other block and then closer together. How does this
affect the center of mass?
The center of mass when farther from each other is still in between the blocks but farther as
well, and when the blocks are closer to each other, the center of mass is closer to each block
while keeping its position in the middle.
2. Explore: Drag a third block on top of one of the first two blocks.
A. How does this affect the position of the center of mass?
The center of mass is in between all three blocks.
B. If the white area of the SIMULATION pane were a tray, where would you put your hand to pick it up?
The middle of the middle block
3. Observe: Set a third block on top of the stack of two blocks. Drag the single block close to and then away
from the stack of three blocks. Observe how the center of mass changes.
A. How did the position of the single block affect the location of the center of mass?
Depending on where the single block is positioned, the center of mass positions itself
around or inside one of the stacked blocks
B. In each case, which object was closer to the center of mass, the stack of three blocks or the single
block? The stacked three blocks
4. Apply: Suppose a heavy person and a light person sat on opposite ends of a see-saw. If they wanted the
see-saw to be balanced, which person would need to sit closer to the fulcrum (the see-saw’s pivot point)?
Explain your answer.
Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved
