Energy, work and heat

Question 1

Define work

Answer 1

Process of energy conversion or transfer

Question 2

Define work done

Answer 2

Work done on a body is defined as the product of the constant force expected on that body and the distance moved by the body in the direction of the force.

Question 3

define energy

Answer 3

the ability to do work (measured in Joules J)

Question 4

define kinetic energy

Answer 4

energy an object possesses by virtue of its motion

Question 5

define potential energy

Answer 5

energy that an object possesses by virtue of its position, condition or state

Question 6

define renewable energy

Answer 6

energy thatt can be replenished naturally

Question 7

define non-renewabe energy

Answer 7

energy that cannot be renewed naturlly

Question 8

define temperature

Answer 8

measurement of the degree of hotness

Question 9

define thermal equilibrium

Answer 9

no net gain/loss of thermal energy between 2 objects (when objects or regions have the same temperature)

Question 10

define conduction

Answer 10

transfer of thermal energy through a medium without any flow of the medium

Question 11

define convection

Answer 11

transfer of thermal energy by means of convection currents in a fluid due to a difference in density

Question 12

define radiation

Answer 12

radiation is the trasfer of energy from a hotter body to a cooler body without the need for a medium

Question 13

define heat insulator

Answer 13

poor conductor of heat

Question 14

define greenhouse effect

Answer 14

process that ours when greenhouse gases in Earth’s atmosphere trap the Sun’s heat, making Earth warmer

Question 15

PRINCIPAL OF ENERGY CONSERVATION?

Answer 15

energy cannot be created or destroyed, but can be transferred from one object to another, or converted from one form to another. The total energy of an isolated system is constant

Question 16

Work done formula

Answer 16

W= FxD
F= W/D
D=W/F

Question 17

Why is 0 work done when pushing against a wall

Answer 17

In this case, although force is exerted, Yes work is done one the wall because the distance moved by the wall is 0

Question 18

Three different forms of kinetic energy

Answer 18

Translational: moving car
Rotational: Wind turbine
Vibrational: Kinetic Particle theory

Question 19

Difference between Heat and Temperature

Answer 19

Heat is a form of energy and temperature is the measurement of the degree of hotness of a body

Question 20

How is temperature related to KE

Answer 20

At higher temperatures, particles move faster as they have more kinetic energy

Question 21

Heat flow

Answer 21

Heat flows from a region of higher temperature to a region of lower temperature.

Question 22

How are conduction and convention similar

Answer 22

The transfer of heat involves the movement of particles

Question 23

What is radiation

Answer 23

The process of energy transfer by eletromagnetic waves. Radiation does not require a medium

Question 24

Conduction

Answer 24

The transfer of of thermal energy through a medium without \any flow of the medium

Question 25

Difference in conductivity between metals and non metals

Answer 25

metals are better conductors of heat. They hve free electrons in their structure which moves randomly among the metal atoms. When metals are heated, in addition to the metal vibratingmore vigorously, the free electrons also gain kinetic energy and move faster, colliding with the atoms in the cooler parts. Atoms in the cooler parts start to ibrate more vigorously, causing the cooler region to become hot faster. Thus, metals conduct heat fatser than non-metals

Question 26

convection

Answer 26

convection is the transfer of thermal energy by means of convection currents in a fluid, due to ifference in densities