General Science: Physics in Everyday Life and Motion

Flashcards covering real-life applications of physics, branches of physics, types of motion, and translational/rotational mechanics equations and calculations.

How is physics defined in General Science Lesson 1?

Physics is the science of matter, energy, and their interactions, explaining how things move, how energy flows or is transformed, and how forces affect the world around us.

What is the distinction between classical physics and modern physics in the lecture?

Classical physics focuses on microscopic phenomena and everyday experiences that involve motion, forces, and energy. Modern physics focuses on microscopic phenomena at high speeds and gravitational fields as it explores the behavior of matter and energy at the atomic level, as well as space, time, and gravity.

What are the five main branches of physics introduced in Lesson 1?

The five branches are Mechanics (studies motion and forces), Thermodynamics (studies heat and energy flow), Electromagnetism (studies electric and magnetic fields), Optics (studies light and its behavior), and Acoustics (focused on sound production and transmission).

How do household air conditioners and electric fans convert energy?

They convert electrical energy into mechanical energy to produce air.

What physics principle allows a refrigerator to keep food cold?

A refrigerator removes heat from food to keep it cold and fresh.

How does a microwave oven heat food quickly?

A microwave oven heats food quickly by using electromagnetic waves.

How does a washing machine use physics to clean clothes?

It applies rotational motion and force to help remove dirt and water from clothes.

How do vehicle airbags protect occupants during a collision?

Airbags increase collision time, reducing the impact force and injury.

What physics principles are utilized by Magnetic Resonance Imaging (MRI)?

MRI uses strong magnetic fields and radio waves to create detailed images of the inside of the body.

What energy transformation occurs in a roller coaster?

A roller coaster converts potential energy into kinetic energy, allowing it to move through hills, loops, and turns.

How does a microphone use physics to process sound?

A microphone converts sound waves into electrical signals that can be amplified or recorded.

How does an ergonomic chair improve comfort using physics?

It supports the body and distributes weight evenly to improve comfort and reduce strain.

How is motion defined in physics?

Motion refers to the change in position of an object over time relative to a frame of reference.

What are the two fundamental types of motion?

Translational motion (moving from one place to another) and rotational motion (turning about an internal axis).

What are the two types of translational motion?

Rectilinear motion (movement in a straight line along a one-dimensional path) and Curvilinear motion (movement in a curved path in two or three dimensions).

What is the formal definition of rotational motion?

It is a type of motion in which all points of a rigid body maintain a constant distance from an imaginary axis and rotate in circular paths about a common axis with a common velocity.

What is the core formula for translational velocity $v$?

$$v = \frac{\Delta s}{\Delta t}$$

A student starts walking from the $15\,\text{m}$ mark of a hallway and stops at the $135\,\text{m}$ mark in $15\,\text{s}$. What is the student's velocity?

The displacement is $\Delta s = 135\,\text{m} - 15\,\text{m} = 120\,\text{m}$. The velocity is $v = \frac{120\,\text{m}}{15\,\text{s}} = 8\,\text{m/s}$.

A cyclist increases speed from $5\,\text{m/s}$ to $25\,\text{m/s}$ in $4\,\text{s}$. What is the cyclist's acceleration?

The acceleration is $a = \frac{25\,\text{m/s} - 5\,\text{m/s}}{4\,\text{s}} = 5\,\text{m/s}^2$.

What is the core formula for torque $\tau$?

$$\tau = F \times r$$

An electric fan increases its angular velocity from $12\,\text{rad/s}$ to $32\,\text{rad/s}$ in $5\,\text{s}$. What is its angular acceleration $\alpha$?

The angular acceleration is $\alpha = \frac{32\,\text{rad/s} - 12\,\text{rad/s}}{5\,\text{s}} = 4\,\text{rad/s}^2$.

A student pushes downward on the end of a $0.60\,\text{m}$-long crowbar with a perpendicular force of $120\,\text{N}$. What torque $\tau$ is exerted on the rock?

The torque is $\tau = 120\,\text{N} \times 0.60\,\text{m} = 72\,\text{N}\cdot\text{m}$.

What bridge formulas link linear distance $s$, linear speed $v$, and centripetal acceleration $a_c$ to angular quantities?

Linear distance is $s = r \times \theta$, linear speed is $v = r \times \omega$, and centripetal acceleration is $a_c = \frac{v^2}{r} = \omega^2 \times r$.

A bicycle wheel with a radius of $0.5\,\text{m}$ turns through an angular displacement of $10\,\text{rad}$ in $2\,\text{s}$. What are its linear distance $s$, linear speed $v$, and centripetal acceleration $a_c$?

Linear distance is $s = 0.5\,\text{m} \times 10\,\text{rad} = 5\,\text{m}$. Angular velocity is $\omega = \frac{10\,\text{rad}}{2\,\text{s}} = 5\,\text{rad/s}$, so linear speed is $v = 0.5\,\text{m} \times 5\,\text{rad/s} = 2.5\,\text{m/s}$. Centripetal acceleration is $a_c = (5\,\text{rad/s})^2 \times 0.5\,\text{m} = 12.5\,\text{m/s}^2$.

A Ferris wheel with a radius of $2.5\,\text{m}$ rotates at constant speed through an angular displacement of $16\,\text{rad}$ in $4\,\text{s}$. What linear distance $s$ does a passenger travel?

The linear distance is $s = 2.5\,\text{m} \times 16\,\text{rad} = 40\,\text{m}$.

A carousel with a radius of $3\,\text{m}$ rotates uniformly through an angular displacement of $20\,\text{rad}$ in $5\,\text{s}$. What is the centripetal acceleration $a_c$ of a rider?

Angular velocity is $\omega = \frac{20\,\text{rad}}{5\,\text{s}} = 4\,\text{rad/s}$. Centripetal acceleration is $a_c = (4\,\text{rad/s})^2 \times 3\,\text{m} = 48\,\text{m/s}^2$.

A bicycle wheel with a radius of $0.8\,\text{m}$ rotates through an angular displacement of $30\,\text{rad}$ in $6\,\text{s}$. What is the linear speed $v$ of a point on the rim?

Angular velocity is $\omega = \frac{30\,\text{rad}}{6\,\text{s}} = 5\,\text{rad/s}$. Linear speed is $v = 0.8\,\text{m} \times 5\,\text{rad/s} = 4\,\text{m/s}$.

A rotating platform with a radius of $4\,\text{m}$ turns through an angular displacement of $28\,\text{rad}$ in $7\,\text{s}$. What linear distance $s$ is traveled by a person standing at the edge?

The linear distance is $s = 4\,\text{m} \times 28\,\text{rad} = 112\,\text{m}$.