Discrepant Activity for - Weight and Gravity concept assessment


Create a picture or diagram with the following to show to students and ask what is happening.

Picture of

  1. a person in the space shuttle orbiting the Earth.
  2. a person in a hot air balloon closer to the Earth.
  3. A person on top of a very tall building.
  4. A person standing on Earth.


  • Ask or identify the location of each person in the picture or drawing.
  • Ask if the student understand where each is supposed to be located?
  • Eather ask the following question for each person in each location and record it or ask the student to record their answers.

Question which of the following experience gravity and or weight?




Person in shuttle


Person in balloon


Person on top of the building


Person standing on Earth


Next a spring scale is put under each person. What would the scale read?


Weight on scale

Person in shuttle


Person in balloon


Person on top of the building


Person standing on Earth


Ask students to summarize, or you summarize what students have previously said to see if they agree.


Not included here.......


Summary of Student Results for Weight and Gravity

Scientific Concepts

  1. Weight is another name for gravitational force.
  2. Weight is the force exerted by an object against a support and is equal to the force exerted by the support on the object.
  3. Weightlessness is never absolute, there is always some, maybe very small weight.
  4. Gravitational force and weight being the same, decrease with increasing distance from the Earth in this case or as the distance between two bodies increases.

Student misconceptions

  • Weightlessness is a result of being in space.
  • Weightlessness only happens in a space vehicle.
  • Weightlessness happens with the absence of air.
  • Weightlessness happens when an object leaves Earth.
  • Emptiness or nothingness creates weightlessness.
  • Free fall near Earth does not have weightlessness.
  • There is an additional force involved with free fall.

Dr. Robert Sweetland's Notes ©