Concept of Linear Momentum
Understanding the definition, formula (p=mv), and units of linear momentum as a vector quantity.
What is Concept of Linear Momentum?
A vector quantity equal to the product of an object's mass and its velocity.
Key formula / rule: Linear Momentum
Key points
- Define linear momentum.
- State the formula for linear momentum.
- Identify the units and dimensions of linear momentum.
- Explain that momentum is a vector quantity.
Common exam trap
Confusing momentum with kinetic energy (both depend on mass and velocity but are different).
Definitions
- Term
Linear Momentum
- Meaning
A vector quantity equal to the product of an object's mass and its velocity.
- Term
Quantity of Motion
- Meaning
A colloquial term often used to describe linear momentum, indicating how much motion an object possesses.
Learning objectives
Define linear momentum.
State the formula for linear momentum.
Identify the units and dimensions of linear momentum.
Explain that momentum is a vector quantity.
Relate momentum to mass and velocity.
Formulae
- Name
Linear Momentum
- Note
p is linear momentum, m is mass, v is velocity. This is a vector equation.
- Expression
p = mv
Prerequisites
Understanding of mass.
Understanding of velocity (speed and direction).
Basic vector concepts.
Common mistakes
Confusing momentum with kinetic energy (both depend on mass and velocity but are different).
Treating momentum as a scalar quantity instead of a vector.
Incorrectly applying the conservation of momentum when external forces are present.
Keywords
Linear momentum
Momentum
Mass
Velocity
Vector quantity
Conservation of momentum
Impulse
Practice preview
Which of the following statements about linear momentum is INCORRECT?…
easy
A car of mass 1000 kg is moving with a velocity of 20 m/s. If the velocity is doubled, what will be the change in its linear momentum?…
medium
Two objects A and B have masses in the ratio 1:2 and velocities in the ratio 2:1. What is the ratio of their linear momenta?…
medium