Unit 2: Motion, Forces & Momentum

Comprehensive vocabulary flashcards covering kinematics, Newton's laws, impulse, momentum, collision types, and conservation laws from Grade 10 Physics Unit 2.

Mass

A measure of how much matter is inside an object, typically measured in kilograms ($\text{kg}$), where more mass corresponds to being heavier and less mass corresponds to being lighter.

Inertia

The property of an object by which it resists any change in its state of motion, which is directly connected to its mass.

Velocity

A quantity that specifies both the speed of an object (how fast it is going) and its direction of motion, distinguishing it from scalar speed.

Speed

A scalar measurement describing how fast an object is moving, without indicating its direction.

Acceleration

The rate of change of velocity over time ($a = \frac{v_f - v_i}{\Delta t}$), occurring when an object speeds up, slows down (comes to a stop), or changes direction.

Net Force ($F_{\text{net}}$)

An unbalanced force acting on an object that causes it to accelerate or speed up in the direction of the force according to $F_{\text{net}} = m a$.

Velocity-Time Graph

A graphical representation of motion where a positive velocity indicates motion in the positive direction, a negative velocity indicates motion in the negative direction, and a velocity of $0\,\text{m/s}$ indicates the object is at rest.

Newton's Second Law

The relationship stating that the net force acting on an object is equal to the product of its mass and its acceleration ($F_{\text{net}} = m a$).

Momentum ($p$)

The measure of mass in motion, calculated as the product of an object's mass and its velocity ($p = m v$).

Impulse ($J$)

The product of the net force acting on an object and the time interval during which it acts ($J = F_{\text{net}} \Delta t$), which is equivalent to the resulting change in momentum ($J = \Delta p = m(v_f - v_i)$).

Average Impact Force

The average net force exerted on an object during a collision, which decreases when the stopping time increases for a given change in momentum.

Elastic Collision

A type of collision in which colliding objects bounce off one another rather than sticking together.

Inelastic Collision

A type of collision in which colliding objects stick together upon impact and travel with a shared final velocity.

Explosion

An event where two or more objects start together at rest and push off each other, moving apart in opposite directions while total momentum remains conserved.

Closed System

A physical system that does not exchange mass with its surroundings and experiences no net external force, ensuring its total momentum remains constant.

Law of Conservation of Momentum

The fundamental principle stating that within a closed system, the total initial momentum before any event or collision is equal to the total final momentum after the event ($m_1 v_{1i} + m_2 v_{2i} = m_1 v_{1f} + m_2 v_{2f}$).