9.5 the scientist

Question 1

list the different types of energy

Answer 1

thermal
chemical
kinetic
nuclear
elastic /strain
gravitational potential

Question 2

the 4 ways energy can be transferred

Answer 2

Mechanically - By the action of a force.

Electrically - By an electrical current.

By radiation - By Light waves or Sound waves.

By heating - By conduction, convection or radiation.

Question 3

how do we reduce friction

Answer 3

use lubricant

Question 4

work: equation

Answer 4

force (N) x distant (M)

Question 5

power (w) = work done (j)/ ?

Answer 5

power (watt) = work done (j)/ time (s)

Question 6

charge (C): equation

Answer 6

current (amps) x time (s)

Question 7

energy transferred (j): equation

Answer 7

charge (Coulombs) x potential difference (volts)

Question 8

energy (j): equation

Answer 8

current (amps) x potential difference (volts) x time (s)

Question 9

power(w) = ? x voltage

Answer 9

power(w) = current x voltage (PIV)

Question 10

power = ? X resistance

Answer 10

power = current^2 X resistance

Question 11

GPE(j): equation

Answer 11

mass x height x g

Question 12

KE(j): equation

Answer 12

1/2 x mass x velocity^2

Question 13

where does conduction, convection and radiation take place?

Answer 13

conduction- solids

convections- fluids

radiation- w/o particles, em waves

Question 14

what does insulating mean

Answer 14

doesnt pass energy on

Question 15

why do we use lubricants

Answer 15

to reduce friction, which reduces the amount of thermal energy that is lost

Question 16

what do periods tell us in a periodic table

Answer 16

the number of electron shells in an atom

Question 17

what do groups tell us in a periodic table

Answer 17

the number of electrons in the outer shell

Question 18

what can graphite be used for and why?

Answer 18

It is a good conductor of electricity. Its high conductivity makes it useful in electronic products because of the delocalised electrons which are free to move and carry an electronic current.

It can also be used as a lubricant because of the weak intermolecular forces which are slippery and can be easily overcome (requires little energy to remove)

Question 19

what can diamonds be used for and why?

Answer 19

Because diamonds are very hard they are often used as an abrasive. Small particles of diamond are embedded in tools and these tools are then used for cutting, drilling, or grinding hard materials.

Diamonds are extremely hard because the outer electron shell of each carbon atom has four electrons, these electrons are shared with four other carbon atoms to form very strong covalent bonds.

Question 20

how does an electric current flow?

Answer 20

when electrons move through a conductor

Question 21

what is 1 amps equivalent to

Answer 21

1 coulomb per second