Does Mass Influence the Amount of Energy an Object

Has?

Experimental Design

• How many variables should be different in a controlled experiment?

• ONE, UNO, 1!!!!!

• What is this variable called?

• Independent Variable- The 1 variable that I change, The 1 variable that we are testing.

• So what is it for this lab?

• Mass

• What variables are we controlling? This means, what could be different in the lab?

• Height of the track.

• Where the steelie is released from (speed).

• Anything else?

• All of these are called Controlled Variables.

• OK, How will we know if mass is effecting Kinetic Energy? What will we measure?

• The distance the tee moves.

• This is called the Dependent Variable, because we think that the distance the tee will move depends on the mass that we use.

What do the results show?

SteelieClass Average

Distance tee was pushed

Big(28.6g)

60.1

Medium(16.2g)

39.2

Small(8.3g)

18.8

Data

0

10

20

30

40

50

60

70

0 10 20 30 40

Series1

Mass (g)

Distance

(cm)

The Answer?

• YES!!!

• The large mass pushed the tee the furthest distance– As mass increased, the amount of work

done also increased– Since both variables increased, mass and

work must have a direct relationship

A New Type of Relationship

• Mass and work also share a second type of relationship, called a linear relationship.

• Compare the distance the tee was pushed by a 10g mass and a 30g mass:– 10g mass pushed tee 22cm– 30g mass pushed tee 68cm

Linear Relationship

• As the mass increased by 3 times (20g to 60g) the work done on the tee also increased by 3 times (22cm to 68cm).– This is known as a linear relationship.– On a graph, a linear relationship is shown

as a straight line

Linear Relationship

• Example # 2

• Compare the distance the tee was pushed by a 20g mass and a 60g mass:– 20g mass pushed tee 27cm– 60g mass pushed tee 88 cm

A New Type of Relationship

• As the mass increased by 3 times (20g to 60g) the work done on the tee also increased by 3 times (27cm to 88cm).– This is known as a linear relationship.– On a graph, a linear relationship is shown

as a straight line

I thought we were trying to show a relationship between mass and kinetic energy…

• The purpose of Lab 1.3 was to determine the type of relationship between mass and KE

• We measured mass and work done (the distance the tee was pushed)

• How can we relate work to KE?

Linking work and KE

• We will use the following mathematical argument to link work and KE:

If A = B

And B = C

Then A = C

Linking Work and KE

• As mass of the steelie increased, work done increased (A = B)

• More work requires more energy to do the work (B = C)

• Therefore, an object with greater mass must have more energy (A = C)