Kinetic Energy
Definition of kinetic energy, its formula (1/2 mv²), and its relation with linear momentum.
What is Kinetic Energy?
The energy an object possesses due to its motion.
Key formula / rule: Kinetic Energy
Key points
- Define kinetic energy.
- State the formula for kinetic energy.
- Calculate kinetic energy given mass and velocity.
- Relate kinetic energy to linear momentum.
Common exam trap
Confusing kinetic energy with potential energy.
Definitions
- Term
Kinetic Energy
- Meaning
The energy an object possesses due to its motion.
- Term
Scalar Quantity
- Meaning
A physical quantity that has magnitude only, not direction.
Learning objectives
Define kinetic energy.
State the formula for kinetic energy.
Calculate kinetic energy given mass and velocity.
Relate kinetic energy to linear momentum.
Understand the units of kinetic energy.
Formulae
- Name
Kinetic Energy
- Note
m = mass, v = velocity
- Expression
KE = 1/2 mv²
- Name
Kinetic Energy in terms of Momentum
- Note
p = linear momentum (mv)
- Expression
KE = p²/2m
Prerequisites
Understanding of mass and velocity.
Basic algebra.
Concept of work and energy.
Linear momentum.
Common mistakes
Confusing kinetic energy with potential energy.
Forgetting to square the velocity in calculations.
Incorrectly applying the relationship with momentum (e.g., assuming direct proportionality instead of squared proportionality).
Using incorrect units.
Keywords
Kinetic Energy
Motion
Velocity
Mass
Work-Energy Theorem
Momentum
Joules
Practice preview
A body of mass 'm' is moving with a velocity 'v'. What is its kinetic energy?…
easy
What is the SI unit of kinetic energy?…
easy
A particle of mass m moving with velocity v collides elastically with a stationary particle of the same mass. What is the kinetic energy of the first particle after collision?…
hard