Physical Science Module 2 & 3 Test Review

Distance

the length an object travels, measured in SI units of meters.

Displacement

distance and direction of an object’s change in position from the starting point

Motion

A change in an object’s position relative to a reference point.

Speed

The distance an object travels per unit of time.

Momentum

A property of a moving object that equals its mass times its velocity.

Velocity

The speed and direction of a moving object.

Acceleration

The rate of change of velocity

Scalar quantity

A quantity that has magnitude but no direction.

Vector quantity

A quantity that has both magnitude and direction.

Field

A region of space where an object experiences a force.

Force

A push or pull on an object.

Friction

A force that opposes motion between surfaces that are touching.

Gravity

The force of attraction between objects with mass.

Net force

The combination of all the forces acting on an object.

Weight

The force of gravity acting on an object.

Mass

A measure of the amount of matter in an object.

Inertia

The tendency of an object to resist a change in its motion.

Static Friction

The force that resists the start of sliding motion between two surfaces that are touching.

Sliding friction

The force that opposes the motion of two surfaces sliding past each other.

Rolling friction

The force that opposes the motion of an object rolling over a surface.

Air resistance

A force that opposes the motion of an object moving through the air.

Newton’s first law of motion

An object at rest stays at rest and an object in motion stays in motion at the same speed and in the same direction unless acted on by an unbalanced force.

Newton’s second law of motion

The acceleration of an object depends on the net force acting on the object and the object’s mass.

Newton’s third law of motion

Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first object.

Centripetal force

The force directed toward the center of a circular path that keeps an object moving in that path.

Free fall

The motion of an object when gravity is the only force acting on it.

Law of conservation of momentum

The total momentum of a system remains constant if no net external force acts on the system.

Terminal velocity

The constant velocity reached by a falling object when the force of air resistance equals the force of gravity.

I apply each of Newton’s Laws to changes in the motion of an object

Newton’s first law states that an object’s motion does not change unless an unbalanced force acts on it. Newton’s second law states that net force equals mass times acceleration (F = ma). Newton’s third law states that when one object exerts a force on another object, the second object exerts an equal and opposite force on the first object.

I can discuss the forces acting on an object that has reached terminal velocity

Gravity acts downward and air resistance acts upward with equal magnitude. The net force is zero, so the object has zero acceleration and continues falling at constant velocity.

I can explain why all objects have the same acceleration due to Earth’s gravity

Ignoring air resistance, all objects near Earth’s surface accelerate downward at approximately 9.8 m/s², regardless of their mass.

I can explain and give examples of each of Newton’s 3 Laws of Motion

Newton’s first law states that an object remains at rest or continues moving at constant velocity unless acted on by an unbalanced force. Example: a soccer ball remains at rest until kicked. Newton’s second law states that acceleration depends on net force and mass (F = ma). Example: kicking a ball harder produces greater acceleration. Newton’s third law states that forces occur in equal and opposite pairs. Example: a swimmer pushes water backward and the water pushes the swimmer forward.

I can apply Newton’s 2nd Law of Motion to the real world and solve problems with it

Use F = ma, where F is net force in newtons, m is mass in kilograms, and a is acceleration in meters per second squared. Rearrange to a = F ÷ m or m = F ÷ a when necessary.

I can apply the Law of Conservation of Momentum to solve problems related to elastic and inelastic collisions between objects

Total initial momentum equals total final momentum when no net external force acts on the system. For two objects, m₁v₁ + m₂v₂ = m₁v₁′ + m₂v₂′.

I can explain how gravitational force between objects is a function of mass and distance

Gravitational force increases as either object’s mass increases and decreases as the distance between the objects increases.

I can determine the relative speed of pairs of objects

For two objects moving in the same direction, subtract their speeds. For two objects moving in opposite directions toward each other, add their speeds.

I can explain how motion is relative to a frame of reference

Motion is described relative to a reference point or coordinate system. The same object may appear to be moving or at rest depending on the observer’s frame of reference.

I know the rate of acceleration due to Earth’s gravity and can use it to solve problems

Near Earth’s surface, acceleration due to gravity is approximately 9.8 m/s² downward. Use this value in motion equations when gravity is the only force causing the acceleration.

I can distinguish between elastic and inelastic collisions

In an elastic collision, total momentum and total kinetic energy are conserved. In an inelastic collision, total momentum is conserved but kinetic energy is not conserved. In a perfectly inelastic collision, the objects stick together.

I know the equation for speed and can apply it to solve real world problems

Speed = distance ÷ time. Average speed = total distance traveled ÷ total time of travel. The SI unit is meters per second (m/s).

I know the equation for velocity and can apply it to solve real world problems

Average velocity = displacement ÷ time. Velocity includes speed and direction and is measured in meters per second (m/s).

I know the equation for momentum and can apply it to solve real world problems

Momentum = mass × velocity, or p = mv. Mass is measured in kilograms and velocity in meters per second. Momentum is measured in kg·m/s.

I know the equation for acceleration and can apply it to solve real world problems

Acceleration = change in velocity ÷ time, or a = (vᶠ − vᵢ) ÷ t. Acceleration is measured in meters per second squared (m/s²).

I can determine the net force acting on an object relative to its motion

Combine all forces acting on an object, accounting for their directions. Add forces in the same direction and subtract forces in opposite directions. Net force = mass × acceleration (F = ma). If net force is zero, velocity does not change.

I can contrast various forms of friction

Static friction prevents surfaces from starting to slide past each other. Sliding friction opposes surfaces sliding past each other. Rolling friction opposes an object rolling over a surface. Air resistance opposes an object moving through the air.

I can interpret distance vs. time, speed vs. time, and acceleration vs. time graphs

On a distance-time graph, the slope represents speed. On a speed-time graph, the slope represents acceleration and the area under the graph represents distance traveled when speed is nonnegative. On an acceleration-time graph, the graph shows how acceleration changes over time.

I can contrast distance and displacement

Distance is the total length an object travels and is a scalar quantity. Displacement is the distance and direction of an object’s change in position from the starting point and is a vector quantity.

I can contrast speed and velocity

Speed is the distance an object travels per unit of time and is a scalar quantity. Velocity is the speed and direction of a moving object and is a vector quantity.

I can contrast weight and mass

Mass measures the amount of matter in an object and is measured in kilograms. Weight is the force of gravity acting on an object and is measured in newtons. Weight = mass × gravitational acceleration.

I can define key vocabulary

Use the exact definitions provided in the vocabulary study guide for each of the 28 key vocabulary terms listed above.