Physics in Daily Life

These flashcards cover the fundamental definitions, household applications, medical imaging technologies, safety mechanisms, and mechanical principles of physics as discussed in the lecture.

What is the definition of Physics provided in the transcript?

The science that deals with the structure of matter and the interactions between the fundamental constituents of the observable universe.

Physics is concerned with nature on which two levels?

The macroscopic and submicroscopic levels.

What energy conversion takes place in an electric fan motor?

A motor converts electrical energy into mechanical energy.

How does an electric fan create airflow?

Electric current flows through coils to create a magnetic field, which spins the motor and rotates the fan blades to push air.

According to the thermodynamics of a refrigerator, what role does evaporation play?

A refrigerant absorbs heat inside the refrigerator through evaporation.

What process occurs when a refrigerator releases heat outside?

Condensation.

What physics concept allows an electric stove or rice cooker to cook food?

Joule heating (resistance heating), where electric current passes through a heating element and resistance produces heat.

How does an LED produce light compared to an incandescent bulb?

In an incandescent bulb, a filament heats up and glows, while in an LED, electrons release energy as light when moving through semiconductors.

How does a television display moving images?

It receives signals and converts them to electrical signals, which are then displayed using light pixels.

What type of waves does ultrasound imaging use?

High-frequency sound waves.

In ultrasound imaging, what is the role of the transducer?

It sends high-frequency sound waves into the body and receives the echoes that bounce off organs and tissues.

Why can X-rays be used to detect bone fractures?

They are high-energy electromagnetic waves that can pass through soft tissues but are absorbed by harder materials like bones.

What is the specific use of a CT Scan (Computed Tomography)?

Detecting tumors and internal bleeding by producing cross-sectional images using multiple X-rays from different angles.

What technology does an MRI use to image soft tissues like the brain or spinal cord?

Radio waves and strong magnetic fields.

Based on Newton’s Laws, why are seatbelts essential for car safety?

They apply force to stop the body safely, preventing passengers from hitting the dashboard or being thrown out of the car due to inertia.

What are the three types of thermal expansion mentioned?

Linear Expansion (length), Area Expansion (surface area), and Volume Expansion (overall size).

How is thermal expansion managed in the construction of railway tracks?

Gaps are left between the rails to allow for expansion.

What is used on bridges to prevent cracking from thermal expansion?

Expansion joints.

What happens to electric wires in hot weather due to thermal expansion?

They sag.

When is 'work' considered to be done in physics?

When a force moves an object over a distance.

What is the formula and unit for Work?

Formula: $\text{Work} = \text{Force} \times \text{Distance}$ ($W = Fd$); Unit: $\text{Joule (J)}$.

Define Power as it relates to physics.

Power is the rate at which work is done, or how fast work is completed.

What is the formula and unit for Power specified in the transcript?

Formula: $\text{Power} = \text{Work} \times \text{Time}$ ($P = Wt$); Unit: $\text{Watt (W)}$.

What physics principal is at play when shooting a basketball?

Projectile motion, where gravity pulls the ball downward and force determines speed and distance.

Which two physics concepts explain the movement of a volleyball during serving or spiking?

Newton's Laws of Motion and momentum.

List the energy concepts applied to roller coasters in amusement parks.

Potential Energy at the top, Kinetic Energy during descent, and the Conservation of Energy throughout the ride.

What forces are acting on passengers as a Ferris wheel rotates?

Gravity pulls passengers downward while the seat supports them, and the wheel provides the force to keep them moving in a circle.