IB DP Physics (2025) A2.1 Contact & Field Forces

IB DP Physics lesson pack on contact and field forces for Topic A.2 Forces and momentum, SL and HL, first assessment 2025: what a force is, the nine forces the course names, and Hooke’s law. Editable worksheet, 56-slide lesson deck, teacher key, worked solutions and a questions-only assessment, supplied as self-contained HTML plus colour and black-and-white PDF.

What students learn

• A force is a push or a pull, one side of an interaction between two bodies: every force is named as the force of one body on another.
• One question sorts the nine forces this course names: do the two bodies have to touch? Contact against field, each with its commonly used symbol.
• Weight, Fg = mg, points towards the centre of the body producing the field, vertically downward only close to the Earth’s surface.
• The normal force stays perpendicular to the surface, tilting on a ramp and horizontal at a wall; a string’s tension pulls along it, at both ends.
• Hooke’s law, FH = -kx, for a stretched and a compressed spring, with k read off the gradient of a force-extension graph.

IB skills (Tool 3: Mathematics, with Inquiry 2: Collecting and processing data):

• Identify and use symbols stated in the guide and the data booklet (taught).
• Draw and label vectors: magnitude, point of application, direction (practised).
• Plot graphs with appropriate scales and axes (practised).
• Draw lines of best fit (practised).
• Interpret gradients and intercepts (practised).
• Apply SI prefixes and units (practised).
• Identify and justify the removal of outliers (practised).

What’s included:

• Student Worksheet - 21 pages
• Teacher Key - 30 pages
• Worked Solutions - 17 pages
• Assessment - 12 pages
• Lesson deck - 56 slides

Fourteen questions and 15 figures: five multiple-choice items and 64 marks of written work, closing on a data-analysis question where the gradient is 1/k and three points are justifiably kept off the line.

Forces are named and drawn one at a time here: free-body diagrams, resultants and Newton’s laws come later in the topic, so nothing in this pack adds forces together. Worksheet and deck open in any modern browser with nothing to install, and the worksheet is fully editable. SI units, IB notation and IB command terms throughout. Suitable for grades 11-12 (ages 16-19) as a lesson, cover lesson, homework or revision.

Related resources:

• Tables, Charts and Graphs, the skill pack behind the plotting and best-fit work
• SUVAT Equations II: Vertical Motion and Gravity, where free fall and g are taught
• Measuring the Acceleration of Free Fall, the practical that measures g (free)
• Foundations of Motion: Distance and Displacement, a free lesson pack to try first