Changing momentum
I can use the equation force = mass × change in velocity ÷ change in time to calculate the size of force involved in changing momentum in a certain amount of time.
Changing momentum
I can use the equation force = mass × change in velocity ÷ change in time to calculate the size of force involved in changing momentum in a certain amount of time.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- The momentum of an object is changed by a resultant force acting over a period of time.
- Force = rate of change of momentum, F = Δp ÷ t = (mv – mu) ÷ t
- The size of an impact force can be changed when the duration of the impact changes.
Keywords
Momentum - is the product of the mass and velocity of an object, p = m v, it is a vector quantity
Initial velocity, u - is the velocity of an object at the start of a phase of motion, represented by u
Final velocity, v - is the velocity of an object at the end of a phase of motion, represented by v
Rate of change of momentum - is the change in momentum per second, this is equal to the resultant force acting on an object
Common misconception
Pupils often confuse the terms force and momentum.
Make explicit the understanding that forces change the motion of an object, and that the motion of an object (that a force can change) can be described by its momentum.
To help you plan your year 11 physics lesson on: Changing momentum, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 11 physics lesson on: Changing momentum, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
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The assessment exit quiz will test your pupils' understanding of the key learning points.
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Explore more key stage 4 physics lessons from the Forces make things change unit, dive into the full secondary physics curriculum, or learn more about lesson planning.
Equipment
Licence
Starter quiz
6 Questions
Exit quiz
6 Questions
momentum -
the product of the mass and velocity of an object, $$p = m × v$$
initial velocity -
the velocity of an object at the start of a phase of motion, $$u$$
final velocity -
the velocity of an object at the end of a phase of motion, $$v$$
rate of change of momentum -
the change in momentum per second, equal to the resultant force