Many students think a heavy or fast-moving object has more force than a light or slow-moving one

Forces and Motion


Furthermore, students may think that evidence for this is provided by the difference between high-speed and low-speed collisions, or between collisions of heavy objects versus collisions of light objects.

Resources to Address This

  • Adding mass to a moving system (11-16)

    Source - Practical physics/ Force and motion/ Momentum

    Drop an extra load onto a moving trolley

    View Resource
  • Episode 221: Elastic collisions (16-19)

    Source - TAP/ Mechanics/ Momentum

    This episode extends the idea of conservation of momentum to elastic collisions, in which, because KE is conserved, useful information can also be found by calculating the changes in KE of the colliding objects.

    View Resource


The following studies have documented this misconception:

  • Brown, D. E. () Students' Concept of Force: The Importance of Understanding Newton's Third Law. Physics Education 24 (6)


    Review sheet

  • Graham, T. and Berry, J. () Students' intuitive understanding of gravity. International Journal of Mathematical Education in Science and Technology, 24 (3),


    This study administered a questionnaire to a sample of 202 students in the UK between the ages of 16 and 18 from a range of city and rural comprehensive schools, private schools and sixth form colleges.
    Review sheet

  • Maloney, D. P. () Rule-governed physics: Some novice predictions. International Journal of Science Education, 7 (3),


    Review sheet

  • Watts, D. M. () A study of schoolchildren's alternative frameworks of the concept of force. International Journal of Science Education, 5 (2),


    This study used an interview approach to identify the conceptions of force of 12 students aged 11-17. Students were drawn from a range of schools in the Greater London area, from both junior science classes and advanced-level physics classes.
    Review sheet

  • Osborne, R. () "Building on Children's Intuitive Ideas" in R. Osborne & P. Freyberg (Eds.), Learning in Science. Heinemann, Auckland.


    Review sheet

  • Twigger, D.; Byard, M.; Driver, R.; Draper, S.; Hartley, R.; Hennessy, S.; Mohamed, R.; O'Mally, C.; O'Shea, T. and Scanlon, E. () The conception of force and motion of students aged between 10 and 15 years: an interview study designed to guide instruction. International Journal of Science Education, 16 (2),


    This study catalogued the responses of 36 students (16 girls and 20 boys) to 7 tasks on an example of motion in a particular context (e.g. kicking a pebble, a falling parachutist, and throwing a ball). The interviews lasted 1 hour and students participated in pairs, in order to encourage discussion. Students were also asked to give individual responses.
    Review sheet

  • Bliss, J.; Ogborn, J. and Whitelock, D. () Secondary school pupils' commonsense theories of motion. International Journal of Science Education, 11 (3),


    This study aimed to expose and empirically test the 'commonsense theory of motion' developed by Jon Ogborn in a sample of 29 students aged 11-18 from two English comprehensive schools. Participants understanding of motion was tested by asking them to describe and explain a sequence of 'comics' depicting physical situations.
    Review sheet

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