Science.2.7.B

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The student is expected to

plan and conduct a descriptive investigation to demonstrate how the strength of a push and pull changes an object's motion.

1666 TEKS header image

Knowledge and Skills Statement

Force, motion, and energy. The student knows that forces cause changes in motion and position in everyday life.

Explain to your students that you will provide each group of students with a cart, a string, and a stopwatch or timer. Ask students to develop a plan for how they might demonstrate how the strength of a push or pull changes an object's motion using those materials. Each group should write their plan down and get it approved by the teacher. Once each group has developed their plan, they should conduct their investigation and record their observations. Students may observe that a gentle push or pull makes the cart move forward slowly while a hard push or pull makes the cart move forward quickly. 
 

The concept of different amounts of forces causing changes in motion is introduced through experiences with different strengths of forces. The concept of balanced and unbalanced forces will be added to this concept at grade 5 through "equal and unequal forces" and will be reinforced in grade 7. When two objects interact, each one exerts a force on the other. These forces can transfer energy between the objects. Forces between two objects at a distance are explained by force fields (gravitational, electric, or magnetic) between them. When the forces acting on an object are balanced (equal in all directions), the motion of the object does not change. When the forces acting on an object are unbalanced (unequal in one or more directions), the motion will change, for example, by changing speed or direction.

Thick and thin arrows representing differences in force
Thick (large) arrows represent a stronger force. Thin (small) arrows represent a weaker force.

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Thin Arrow: Icon made by Handicon from www.flaticon.com
Thick arrow URL: https://www.flaticon.com/free-icon/right-arrow_271226?term=arrow&page=1&position=5&origin=search&related_id=271226
Thin arrow URL: https://www.flaticon.com/free-icon/right-arrows_2989981?term=arrow&page=1&position=36&origin=search&related_id=2989981

a type of investigation that involves simple observations to understand and explain a process or behavior

a push or pull between two objects

an act, process, or instance of changing position or location

the point or area occupied by a physical object; typically a number on an axis

a force between two objects that may cause a change in motion toward the object exerting the pulling force

a force between two objects that may cause a change in motion away from the object exerting the pushing force

Research

 Wilcox, Jesse, Naryah Moore, Sarah Nolting, Courtney Reyna, and Caitlyn Potter. "Don't Force It!: Using Guiding Questions to Scaffold Kindergartner’s Thinking of Pushes And Pulls." Science and Children 59, no. 2 (2021): 33-37. https://www.jstor.org/stable/27133371.

Summary: This article explains the importance of questioning strategies and gives examples of how to do so when teaching the concept of push and pull. It states that teachers should avoid using "yes" or "no" questions instead of focusing on using age-appropriate open-ended questions. Physical examples are important when presenting a push-and-pull activity, specifically everyday examples, like children playing with sleds. Probing questions can help students predict what will happen and what will make an object move faster or slower. Teachers should have students predict what will happen if different variables are changed. Asking effective questions can help students generate ideas about force and motion.