Physics 1 - Fall Semester Review 2024

Independent Variable

The variable that is changed or controlled in a scientific experiment.

Dependent Variable

The variable that is measured and affected in an experiment.

Significant Figures

The digits in a number that are necessary to express it accurately.

Scalar

A quantity that has magnitude only, such as speed or distance.

Vector

A quantity that has both magnitude and direction, such as velocity or displacement.

Constant Velocity

Motion at a fixed speed in a straight line.

Acceleration

The rate of change of velocity per unit time.

Newton's 1st Law

An object at rest remains at rest, and an object in motion stays in motion unless acted upon by a net external force.

Newton's 3rd Law

For every action, there is an equal and opposite reaction.

Free Body Diagram

A diagram showing all the forces acting on an object.

Net Force

The overall force acting on an object after all the forces are combined.

Centripetal Force

The force required to keep an object moving in a circular path.

Momentum

The product of an object's mass and its velocity.

Impulse-Momentum Theorem

The impulse on an object is equal to the change in its momentum.

Conservation of Momentum

In a closed system, the total momentum before an event must equal the total momentum after.

Elastic Collision

A collision in which kinetic energy is conserved.

Inelastic Collision

A collision in which kinetic energy is not conserved.

Perfectly Inelastic Collision

A collision where two objects stick together after the collision.

Centripetal Acceleration

The acceleration directed towards the center of a circular path.

Slope of a Graph

The ratio of the change in the dependent variable to the change in the independent variable, indicating the rate of change.

Kinematic Equations

Equations that relate the motion of an object to its displacement, velocity, acceleration, and time.

Displacement

The change in position of an object, measured as a straight line from the starting point to the final point, including direction.

Three Ways an Object Can Accelerate

An object can accelerate by increasing speed, decreasing speed (deceleration), or changing direction.

Acceleration from a Velocity-Time Graph

The acceleration of an object can be calculated from the slope of the line on a velocity-time graph.

Calculate Acceleration Using Kinematic Equations

Acceleration can be calculated using kinematic equations that relate displacement, initial velocity, final velocity, and time.

Average Velocity in Uniform Acceleration

The average velocity of an object under uniform acceleration is the midpoint of the initial and final velocities.

Area of a Velocity-Time Graph

The area under a velocity-time graph represents the displacement of the object.

Position-Time Graph Shapes for Accelerations

A position-time graph shows a curve for acceleration; it slopes upward for positive acceleration and downward for negative acceleration.

Comparing Acceleration Graphs

By analyzing the steepness of the slopes of different graphs, one can determine which object is accelerating more.

Acceleration Due to Gravity

The acceleration due to gravity is approximately 9.81 m/s² towards the center of the Earth.

Objects in Free Fall

Objects in free fall experience only the force of gravity, regardless of their mass, and accelerate downward at 9.81 m/s².

Final Speed of a Freely-Falling Object

The final speed of a freely-falling object can be calculated using the formula: final speed = initial speed + (acceleration due to gravity × time).

Resolving Vectors into Components

Breaking a vector into its horizontal and vertical components to analyze its effects in those directions.

Resultant Vector

The vector that results from adding two or more vectors together, representing the total effect.

Force Diagram Description of Motion

A visual representation showing all the forces acting on an object, helping to identify its motion direction and magnitude.

Types of Forces Acting on an Object

Forces such as gravitational force, normal force, frictional force, tension, and their respective directions acting on an object.

Action-Reaction Pairs (3rd Law)

For every action exerted by one object, an equal and opposite reaction is exerted by another object.

Components of Tension Force

To calculate components of a tension force, use trigonometric functions based on the angle of the force applied.

Forces on an Object on a Ramp

Calculating forces involves analyzing gravitational force, normal force, and frictional force acting on the object along the ramp.

Acceleration Using 2nd Law

Acceleration can be calculated using the formula: F = ma, where F is the net force and m is mass.

Net Force from Free-Body Diagram

The net force is obtained by vectorially adding all forces depicted in a free-body diagram.

Normal Force in an Elevator

The normal force on a person in an elevator varies with acceleration; it can be calculated using F = mg + ma, where g is gravitational acceleration.

Calculating Motion Variables

Use net force (F = ma) and known variables to find unknowns like acceleration, final velocity, initial velocity, time, or displacement.

Variables Affecting Friction Force

Friction force depends on the normal force and the coefficient of friction between surfaces in contact.

Coefficient of Friction Calculation

The coefficient of friction can be calculated as the ratio of the frictional force to the normal force.

Path of a Projectile

A projectile follows a parabolic trajectory due to the influence of gravity and its initial velocity.

Horizontal and Vertical Acceleration of a Projectile

In projectile motion, the horizontal acceleration is zero, while the vertical acceleration is equal to the acceleration due to gravity.

Range of a Projectile

The range is affected by initial height and horizontal velocity; higher launch angles increase height but decrease horizontal distance.

Force Diagram in Projectile Motion

A force diagram for projectiles shows gravity acting downwards and initial velocity at an angle during the launch.

Penny on Rotating Platform

A penny stays on a rotating platform if the centripetal force is sufficient; otherwise, it flies off due to inertia.

Speed in Uniform Circular Motion

The speed of an object in uniform circular motion remains constant but its direction changes continuously.

Acceleration in Uniform Circular Motion

The acceleration is directed towards the center of the circular path and is known as centripetal acceleration.

Centripetal Force Calculation

Centripetal force can be calculated using the formula: F_c = (mv²)/r, where m is mass, v is speed, and r is radius.

Direction of Net Force in Circular Motion

The net force in uniform circular motion always points towards the center of the circular path.

Direction of Instantaneous Velocity in Circular Motion

The instantaneous velocity is tangent to the circular path, indicating the direction of motion at any point.

Direction of Acceleration in Circular Motion

Centripetal acceleration always points inward towards the center of the circle.

Calculate Momentum of Objects

Momentum is calculated as the product of an object's mass and its velocity: p = mv.

Collision Predictions with Masses and Velocities

Comparing masses and velocities helps predict outcomes such as post-collision speeds and directions.

Impulse to Stop an Object

Impulse required to stop an object equals the change in momentum, calculated as: impulse = force x time.

Conservation of Momentum in Collisions

Momentum is conserved in closed systems, allowing the calculation of final velocities after explosions or collisions.

Relationship between Time and Force in Impulse

Impulse involves both force and time; a larger force or longer time results in greater impulse.