Practice Hub

Flash Cards: WORK, ENERGY AND POWER

This chapter explains the concepts of work, energy, and power, which are essential for understanding physical systems.

Structured practice

WORK, ENERGY AND POWER - Flash Cards

These flash cards cover important concepts from WORK, ENERGY AND POWER in Physics Part - I for Class 11 (Physics).

1/18

What is the definition of work in physics?

1/18

In physics, work is defined as the product of the force applied on an object and the displacement of that object in the direction of the force. Formula: W = F × d × cos(θ), where θ is the angle between the force and displacement vectors.

How well did you know this?

Not at allPerfectly

2/18

What is the SI unit of work?

2/18

The SI unit of work is the Joule (J). One Joule is defined as the work done when a force of one newton displaces an object by one meter in the direction of the force.

How well did you know this?

Not at allPerfectly
Active

3/18

What is energy in physics?

Active

3/18

Energy is the capacity to do work. It exists in various forms such as kinetic energy, potential energy, thermal energy, etc.

How well did you know this?

Not at allPerfectly

4/18

What is the formula for kinetic energy?

4/18

The formula for kinetic energy (KE) is KE = (1/2)mv², where m is mass and v is the velocity of the object.

5/18

Define potential energy.

5/18

Potential energy is the energy possessed by an object due to its position or configuration. For gravitational potential energy: PE = mgh, where m is mass, g is acceleration due to gravity, and h is height above a reference point.

6/18

What does the work-energy theorem state?

6/18

The work-energy theorem states that the work done by the net force acting on an object is equal to the change in its kinetic energy.

7/18

How is power defined in physics?

7/18

Power is defined as the rate at which work is done or energy is transferred. Formula: Power = Work done / Time taken.

8/18

What is the SI unit of power?

8/18

The SI unit of power is the Watt (W). One Watt is equal to one Joule per second.

9/18

What is the scalar product of two vectors?

9/18

The scalar product (or dot product) of two vectors A and B is given by A · B = |A||B| cos(θ), where θ is the angle between the vectors. It results in a scalar quantity.

10/18

What is the commutative property of the scalar product?

10/18

The scalar product follows the commutative property: A · B = B · A.

11/18

State the distributive property of the scalar product.

11/18

The distributive property states: A · (B + C) = A · B + A · C.

12/18

What is the scalar product of two perpendicular vectors?

12/18

If two vectors A and B are perpendicular, then A · B = 0.

13/18

How to calculate work done in lifting an object?

13/18

The work done in lifting an object is calculated using W = mgh, where m is the mass, g is the acceleration due to gravity, and h is the height lifted.

14/18

What is the principle of conservation of energy?

14/18

The principle states that energy cannot be created or destroyed, only transformed from one form to another.

15/18

What is the difference between work and energy?

15/18

Work is the transfer of energy through force applied over a distance, while energy is the capacity to perform work.

16/18

Provide an example illustrating power.

16/18

Running up the stairs quickly requires more power than walking up because power is the rate of doing work; more work is done in less time.

17/18

Is work done when force is applied but no movement occurs?

17/18

No, work is only done when an object moves in the direction of the applied force. If there is no displacement, work done is zero.

18/18

What is the relation between work and energy?

18/18

Work done on an object results in a transfer of energy to that object, changing its kinetic energy or potential energy.