Energy, Work And Power

Question 1

What is work

Answer 1

Force applied over distance

Question 2

What are the units for work

Answer 2

Joules

Question 3

What are the units for energy

Answer 3

Joules

Question 4

What are the units for power

Answer 4

Watts

Question 5

When is no work done

Answer 5

No work is done if no distance is covered in the direction of the force applied

Question 6

In order for work to be done what must be true about force and distance

Answer 6

Force and distance must be in the same direction

Question 7

What is a joule

Answer 7

Newton* meters

Amount of energy needed to apply one Newton of force/ one meters distance

Question 8

Any time work is done what must be used

Answer 8

Energy must be used to do work

Question 9

Define energy

Answer 9

Energy is the ability to do work

Question 10

What are the different categories of energy

Answer 10

Kinetic and potential

Question 11

What is kinetic energy

Answer 11

Kinetic energy is the energy if motion, ex

Sound, light, heat, moving objects, electricity

Question 12

What is potential energy

Answer 12

Potential is the energy of position or stored energy
Ex
Chemical energy, gpe, energy of position, but

Question 13

What is the formula for kinetic energy and what variable matters most

Answer 13

KE= 1/2mV(2)

Most influential is velocity

Question 14

What is the formula for potential energy and what variable is most valuable

Answer 14

GPE= w*h

Height is the most influential

Question 15

What is the law of conservation go energy

Answer 15

Law of conservation of energy states that energy cannot be crated or destroyed only converted from one form to another

Question 16

How does the law of conservation of energy relate to potential and kinetic energy

Answer 16

In the roller coaster lab, PE is converted to KE as the marble rolls down hill, KE is converted to PE as the marble rolls up hill

Question 17

If a roller coaster cars mass is doubled what happens to the amount of kinetic and potential energy that the car will have

Answer 17

Doubling the mass of the car doubles the potential energy at the top and therefore doubles the speed at the bottom

Question 18

If the cars velocity is doubled what will happen to the kinetic and potential energy

Answer 18

Doubling the velocity will mean the car has 4x as much energy

Question 19

As an object falls what happens to the value of potential energy

Answer 19

Potential decreases as an object falls (less hieght=less PE)

Question 20

As an object falls what happens to the value of kinetic energy

Answer 20

KE increases as an object falls because it’s velocity is increasing as PE is being converted into KE

Question 21

What is the energy transformation in lighting a match

Answer 21

Chemical energy to heat and light

Question 22

What is the energy transformation in turning in a light

Answer 22

Electrical energy to light

Question 23

What is the energy transformation in starting a car

Answer 23

Chemical energy to kinetic energy of moving energy

Question 24

What is the energy transformation in walking up stairs

Answer 24

Chemical energy to kinetic energy of moving body

Question 25

What is the energy transformation in playing a piano

Answer 25

Chemical energy to kinetic and sound, moving fingers to moving strings into sound

Question 26

What is the formula for work

Answer 26

w=f*d

Question 27

What is the formula for power

Answer 27

P= w/t
P= f*d
——–
T

Question 28

If you have a 50kg object and lift it a distance of 10 meters how much work so you do on the object, how much power of you do it in four seconds?

Answer 28

W= 5,000j
P= 1250watts

Question 29

If you exert 150 joules of energy in 15 seconds, what is your power

Answer 29

P= 10 watts

Question 30

What is the difference between work and power

Answer 30

Work is done when energy is converted from one form to another, power is how fast the energy is converted or how fast the work is done

Question 31

What is gpe

Answer 31

Potential to fall