Friction and Motion

In the final unit of Kindergarten, students explore how forces and how different factors can affect an object’s motion. They explore how objects move in different directions when they are pushed or pulled, and then investigate how changing the strength of a force changes the distance an object moves. Finally, students discover how friction can change motion.

This page is a high-level extract from lesson three in which students carry out an experiment to examine how the texture of different surfaces can change the motion of a rolling marble.

Science Background for Teachers:

This background gives teachers more in-depth information about the phenomenon students will explore in the lesson. It helps teachers be fully prepared to ask and answer higher order thinking questions with the students.

Contact forces cause objects to change their motion because they transfer energy into or out of an object or system. Energy is the ability to do work, which is any change in position, speed, or state of matter due to force. There are two categories of energy: energy that is stored, called potential energy, and the energy of motion, called kinetic energy. For example, living things need food because food holds a form of potential energy called chemical energy. When animals, including humans, eat we absorb that chemical energy. When we move, that chemical energy changes to kinetic energy.

Friction is why your hands feel hot after you rub them together. It’s important to point out that energy isn’t disappearing as a result of friction. Instead, it’s transferring out of the system. Heat is evidence that energy has transferred out of the system and into the surrounding environment. Friction holds back the movement of a sliding object. When a car stops at a traffic light, the friction between the brakes and the wheels slows it down. When you run down the sidewalk, the friction between your shoes and the cement slows you down. How fast an object moves is its speed. It is the rate at which an object covers distance in a period of time. Speed is the ratio of distance traveled to time taken, which means it can be found by dividing the distance traveled by the time spent traveling. It is measured in meters per second (m/s).

Supports Grade K

Science Lesson: Understanding Friction and Motion

In this unit, students explore forces and motion. Once students have investigated the effects of pushes and pulls, they build on their understanding of forces and motion as they plan and conduct an experiment to observe how the distance a cup moves across the floor changes when it is pushed with a large force compared to a small force.

In this lesson, students continue to explore forces, focusing on friction, which is a force that slows movement by turning motion energy into heat. Students carry out an experiment to examine how the texture of different surfaces can change the motion of a rolling marble.

Science Big Ideas

  • A force is needed to cause an object to slow down or stop once it is moving.
  • Friction is a force that slows motion because it turns the energy of motion into heat.
  • An object will move at a faster speed when it moves over surfaces that produce less friction.

Sample Unit CTA-2
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Science Essential Questions

  • What is friction and how does it affect the motion of an object?
  • Why do moving objects eventually slow down and stop?
  • Why do rougher surfaces make more friction?
  • What does it mean that something has a lot of speed? What objects have you seen that have a lot of speed?
  • Do marbles roll farther on a smooth surface or a rough surface when pushed with the same amount of force?

Common Science Misconceptions

Misconception: Constant motion requires a constant force.

Fact: Once a force causes an object to move, that object will continue to move until another force acts on it, causing it to change its motion.

Misconception: Moving objects stop when the force moving them “runs out.”

Fact: Objects only change their motion by force. For example, objects slow down because of the force of friction. Without a force to change its motion, a moving object would continue moving forever.

Science Vocabulary

Energy : the ability to do work

Friction : a force that slows motion when two objects rub against each other

Speed : how fast an object moves

Lexile(R) Certified Non-Fiction Science Reading (Excerpt)

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Hands-on Science Activity

As the main activity of this lesson, students carry out an experiment to determine how friction affects motion. Students make predictions/hypotheses about how far a marble will go on different types of surfaces (smooth and rough). They then test their hypotheses through experimentation and discuss their findings.

Science Assessments

KnowAtom incorporates formative and summative assessments designed to make students thinking visible for deeper student-centered learning.

  • Vocabulary Check
  • Lab Checkpoints
  • Concept Check Assessment 
  • Concept Map Assessment 
  • And More...

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Science Standards

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Discover hands-on screens-off core science curriculum for student centered K-8 classrooms. KnowAtom supports classrooms with all hands-on materials, curriculum, and professional development to support mastery of the standards.

Download the Alignment to NGSS

Standards citation: NGSS Lead States. 2013. Next Generation Science Standards: For States, By States. Washington, DC: The National Academies Press. Neither WestEd nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of this product, and do not endorse it.