WORK ENERGY AND POWER

Question 1

Define work.

Answer 1

Work is set to be done when force is applied on the body gets displaced in the direction of force.

Question 2

Define the SI unit of work.

Answer 2

The SI unit of work is Newton meter or Jules. One Joule is the amount of work done on an object when the object of 1 Newton displaces it by 1 meter along the line of action of force.

Question 3

Define energy

Answer 3

Energy is the capacity to do work.

Question 4

Define the SI unit of energy.

Answer 4

The energy possessed by an object is thus measured in terms of the capacity of doing work. The unit of energy is the same as work that is, jewel. One Joule is the energy required to do 1 Joule of work sometimes a larger unit of energy called KJ is used.

Question 5

Forms of energy

Answer 5

Mechanical energy, heat energy, chemical energy, electrical energy, light energy

Question 6

Define kinetic energy.

Answer 6

Energy possessed by a body by the virtue of its motion. Anybody that process energy is called kinetic energy

Question 7

Define elastic potential energy.

Answer 7

Energy processed by body by the virtue of change in its shape, our configuration is called elastic potential energy.

Question 8

Define potential energy.

Answer 8

Energy possessed by body by virtue of its height or position is called gravitational potential energy.

Question 9

What is the law of conservation of energy.

Answer 9

• energy can only be converted from one form to another it can neither be created nor destroyed.
• whenever energy is transferred, the total energy remains unchanged. This is the law of conservation of energy.

Question 10

Define mechanical energy.

Answer 10

• the sum of kinetic energy and potential energy of an object is called its mechanical energy.

Question 11

What is the commercial unit of energy.

Answer 11

• to express large quantities of energy we use kWh.
• the energy used in one hour at the rate of 1 kilowatt is called one kWh.
• the electrical energy used during a month is expressed in terms of units.

Question 12

Relationship between kWh and joules.

Answer 12

1 kWh=3.6 x 10⁶ J

Question 13

Define power

Answer 13

Power is defined as the rate of doing work or the rate of transfer of energy.

Question 14

The unit of power is watt in honor of

Answer 14

James Watt

Question 15

Define SI unit of power

Answer 15

1 watt is the power of an agent which does work at the rate of 1 Joule per second.

Question 16

What is the work energy theorem.

Answer 16

The work done by all the forces acting on the body is equal to the change in this kinetic energy.