Chapter 2 Flashcards

Flashcards with questions and answers about the lecture notes.

What is needed to determine the position of an object in the universe?

A fixed point is needed.

When is an object said to be at rest?

When the position of an object does not change relative to its surroundings over time.

Is it possible to find a reference object that is truly at rest in the universe?

No, it is impossible.

What is the motion of an object relative to an absolutely at-rest reference object called?

Absolute motion.

What is relative motion?

The motion of a moving train relative to a railway station.

Give an example of relative rest.

The position of a book on a table.

What is linear motion?

The motion of a car on a straight road.

Give examples of rotational motion.

The motion of an electric fan, the hands of a clock, the motion of the Earth, and the motion of the Moon.

Give examples of vibrational motion.

The motion of a swinging child, a guitar string, and a simple pendulum.

Give examples of periodic motion.

The motion of the Earth around the Sun, the motion of a piston in a cylinder, the motion of clock hands, and vibrational motion.

What are the dimensions of work and energy?

[ML²T‍²]

What is the unit of work and energy?

Joule (J)

What is the most common form of energy?

Mechanical energy

What are the two parts of mechanical energy?

Potential energy and kinetic energy

Considering the amount, what type of energy transformation occurs most on Earth?

Heat energy

When is work done primarily due to kinetic energy?

Due to the motion of an object.

Where does kinetic energy start?

Just before it starts moving.

Just before an object hits the ground, what is its kinetic energy equal to?

Its maximum potential energy, which is equal to the total mechanical energy.

If the mass of an object is increased by X times and its velocity is increased by Y times, how much will it increase?

Its kinetic energy will be XY² times the original kinetic energy.

If the mass of an object is halved and its velocity is quadrupled, how much will it increase?

Its kinetic energy will be 8 times of the original kinetic energy.

Why is kinetic energy always positive?

Because mass (m) and the square of velocity (v2) are always positive.

If the mass is m, initial velocity is u, final velocity is v, and work done is W, what is the formula?

½mv² = ½mu² + W

Is the kinetic energy of an object proportional to its velocity?

No, it's proportional to the square of its velocity. Kinetic energy, T x v².

If the velocity of an object is 2 ms 1, what will be equal?

Its momentum and kinetic energy will be equal.

If the kinetic energy of an object increases by n times, what velocity is expected?

Its velocity increases by √n times.

If the kinetic energy increases by 9 times, does the velocity increase?

The velocity increases by √9 = 3 times.

When is potential energy stored?

When an object is compressed, potential energy is stored in it.

When is kinetic energy zero?

When a spring is stretched from its equilibrium position.

What is the energy condition at the equilibrium position?

Kinetic energy is maximum, and the potential energy is zero.

What are the units of all forms of energy?

Joule (J), and their dimensions are ML2T-².

The unit of potential energy

Joule (J).

The dimension of potential energy

ML²T-².

Dimension of kinetic energy

ML²T-2.

Kinetic condition for a falling object

Its potential energy decreases, and its velocity and kinetic energy increase.

The condition for lifting an object

potential energy is stored in it.

Describe the transfer of energy for a falling ball

potential energy is converted into kinetic energy.

What are the units of surface tension?

Joule/meter² (Jm²), Newton/meter (Nm¹), Kilogram/second² (kgs²)

What happens to the spring constant?

If a spring is cut into two equal parts, its spring constant increases.

What % of Earth's energy resources are renewable?

About one-fifth

What is included in renewable energy sources?

Solar energy, Wind energy, Hydroelectric energy, Geothermal energy, Biomass energy

What is true of water?

Water is a renewable energy source.

What is used to generate electricity?

Solar energy.

Types of Non-renewable energy

Coal, Oil, Natural gas, Nuclear energy

True of Fossil fuels

Fossil fuels are non-renewable energy sources.

What components generate electricity?

Steam turbines

What can generate electricity?

Solar energy.

What is involved in nuclear energy research?

The Bhabha Atomic Research Centre (BARC)

What happens when energy is converted?

Heat is produced. This heat can be converted into mechanical energy.

What happens in creating electricity?

mechanical energy is used to rotate the turbine, which converts mechanical energy into electrical energy.

What happen when a generator is rotated?

electrical energy is produced.

Direction movement in a circuit?

potential energy increases in any direction.

What happens when a child swings?

potential energy increases in any direction.

What kind of energy is converted in a piston?

mechanical energy is converted into kinetic energy.

What is the formula is the mass-energy equivalence formula?

E = mc². This formula allows mass to be converted into energy.

What is the amount of antimatter?

The amount of antimatter in the universe is 0.7%.

What fuels are used in nuclear reactors?

Uranium-235, which has 92 protons and 143 neutrons.

What controls the nuclear reactions?

special types of rods called control rods are used

Fission of Uranium-235

3 neutrons are released in the second stage.

True of power

Power is the product of force and velocity.

What is the dimension of power?

ML²T‍³.

Is Horsepower (H.P.) used to measure power?

Yes

formula for Effective power

Total power - Wasted power.

formula for Efficiency

(Work done / Total power) × 100% = (Total power - Wasted power) / Total power × 100% = (E- E₁)/E × 100%.