Oscillations and Vibrations l

Question 1

What is Energy?

Answer 1

Ability to do work, such as the capacity to move an object by using force.

Question 2

What is the S.I unit of energy?

Answer 2

J (Joule)

Question 3

What is Kinetic Energy?

Answer 3

Form of energy that an object has by reason of its motion. Objects that speed up gain Kinetic Energy.

Question 4

What is the abbreviation for kinetic energy?

Answer 4

Ek (in J)

Question 5

What is potential energy?

Answer 5

Stored/ Latent Energy

Question 6

What is the abbreviation for Gravitational potential energy.

Answer 6

Eg

Question 7

What is the abbreviation for Elastic potential?

Answer 7

Es

Question 8

Describe gravitational potential energy.

Answer 8

Potential energy that makes something have a tendency to fall down.

Question 9

What is the formula for Eg?

Answer 9

Eg = mgy
g= acceleration due to gravity in m/s2
y =height above some reference height

Question 10

What is the formula for Ek?

Answer 10

Ek= 1/2mv2

Question 11

Describe the energy transformation of a dropped object when it is about to be DROPPED.

Answer 11

Ek = 0 (since v=0)
EG = Max

Question 12

Describe the energy transformation of a dropped object when it is about to be HIT THE GROUND.

Answer 12

Ek =Max
EG= 0 (since y=0)

Question 13

As object falls, it loses _______________ energy and gains ________ energy.

Answer 13

As object falls, it loses gravitational potential energy and gains Kinetic energy.

Question 14

As object falls and accelerates, the ___________ energy is being transformed into ________ energy.

Answer 14

As object falls and accelerates, the gravitational potential energy is being transformed into kinetic energy.

Question 15

True or False: the total energy of a dropped object is CONSERVED and remains constant?

Answer 15

True!
Etotal(stays the same) = EG (decreases) + Ek(increases)

Question 16

What is Elastic potential energy?

Answer 16

Potential energy that an object has when it is displaced from its equilibrium position.

Question 17

What are three ways we can call the type of FORCE in the Es?

Answer 17

Elastic force
Spring force
Restoring force

Question 18

What is the abbreviation of Elastic potential energy?

Answer 18

Es

Question 19

What does Fs stands for? Draw a diagram.

Answer 19

It is the elastic force that pulls object back towards 0. (in N)

Question 20

The amount of elastic force for a spring is very predictable, what is it called?

Answer 20

Linear elastic behavior

Question 21

What is Hooke’s Law?

Answer 21

Hooke’s law, law of elasticity states that, for relatively small deformations of an object, the deforming force will be proportional to the size of the deformation (ex: 2m of deformation will yield 2Fs)

Question 22

What is the formula for elastic force?

Answer 22

Fs= -kx
Fs= elastic force (in N)
x = distance of displacement (in m)
k = elastic constant (in N/m)

Question 23

What is the difference between a + and - in the formula Fs= +kx and Fs=-kx Draw it!

Answer 23

The force always acts in a direction that is opposite of the objects displacement direction.

Question 24

What is the formula for elastic potential energy?

Answer 24

Es= 1/2kx2
Es in J
k= elastic constant N/m

Question 25

Give three materials that possess elasticity.

Answer 25

Springs
Cheeks
Elastic bands

Question 26

When an elastic material is compressed or expanded it possess ____________ energy.

Answer 26

elastic potential energy

Question 27

When the material/ object is released, that elastic potential energy begins to be transformed into _______________.

Answer 27

Kinetic energy (the elastic material begins to move)

Question 28

What is work?

Answer 28

Work is done by a force on an object to make it move.

Question 29

What is the abbreviation of work?

Answer 29

W (in Joules)

Question 30

What would be an example of doing work by kicking?

Answer 30

If I kick it, I am working on it and making it gain Ek (O+ Wkick= Ek)

Question 31

What would be an example of doing work to move an object on a table.

Answer 31

As the object moves along the table top, it slows down because friction does negative work on it, making it lose Ek (Ek+(-Wfriction) = ))

Question 32

How do you find the Total mechanical energy at the end of a work process?

Answer 32

Etme(initially) + W = Etme (at the end)

Question 33

What is the formula of Work?

Answer 33

W = F.d.cosθ
W in J
F in N
d distance object moves m
θ = angle between the force and the direction of motion of object (in degrees)

Question 34

If θ is = 0 what does it mean in terms of the direction of work?

Answer 34

If θ the angle between the direction of motion and the force is 0 than 100% of that force will go in that direction.

Question 35

What is Power?

Answer 35

Rate at which energy is produced or consumed/used.

Question 36

What is the formula for Power?

Answer 36

P = E/t
E in J
t in s

Question 37

What is intensity?

Answer 37

Measure of how power is distributed spatially (thus how energy is distributed in space)

Question 38

What is the formula for intensity?

Answer 38

I= PA
I in W/m2
Power in W
A in m

Question 39

What is the formula of power for an isotropic source?

Answer 39

I = P/4.pi.r2
r in m

Question 40

An ____________ source of a sound wave produces _______ wavefronts

Answer 40

An isotropic source of a sound wave produces equal wavefronts on all sides

Question 41

In an isotropic source, for every distance r around the object, the energy should be __________________.

Answer 41

Evenly distributed

Question 42

What is the name of the restoring force of springs?

Answer 42

Elastic force

Question 43

What is the name of the restoring force of a pendulum?

Answer 43

gravity

Question 44

What is the name of the restoring force of a tuning fork?

Answer 44

elastic force

Question 45

Energy can be __________or __________from one form to another.

Answer 45

Transformed or Transferred