Try this at home!

School blocks YouTube? Use the link below

| Onsite |

 

 

 

 

D) Law of Conservation of Energy - unless work is done on or by a system, its total mechanical energy does not change.

 

- Paul Hewitt

 

 

Was energy created in this video?

Girl goes flying After the biggest piggy back blob jump

School blocks YouTube? Use the link below

BlobLaunch.mov

 

 

 

 

The massive PE of the men on the platform completely turned into KE at the bottom of their jump.

The boy on the blob has more KE but less PE than the man.

 

 

 

 

1. Total Mechanical Energy

 

= PE + KE

 

  

Ex 1) Falling object(no friction)

 

 

Answer

 

 

As the Object Falls,

 

 

PE Lost = ....

 

 

...KE gained

 

 

 

 

Predict how far up the

incline each ball will go.

(assume no friction)

 

Click here if you have an iphone or ipad

 

 

Why does each ball rise

to the same height

 from which it began?

 

 

 

 

 

 

PE depends only on

height. Ball stops when

 all KE turns into PE

 

 

Energy changes
in a roller coaster

- Teachers Domain

 

 

Ex 2)

 

 

IF KE at A = 0

 

PE = ?

 

PE = mgh,

g = 10 m/s2

PE = 3 kg(10 m/s2)3 m

= 90 J

  PE KE
A 90 J 0

 

B?

 

m = 3 kg, h = 1 m

B PE KE
 

 

 

30 J












60 J

 

 

C?

 

 

m = 3 kg, h = 0

C PE KE
 

 

 

0 J

(h = 0)






90 J

 

 

 

D?

 

m = 3 kg, h = 1 m

D PE KE
 

 

 

30 J







 

 

 

60 J

 

 

 

m = 3 kg, h = 0

E PE KE
 

 

0 J

(h = 0)







90 J

 

m = 3 kg, h = 1 m

F PE KE
 

30 J









60 J

 

 

m = 3 kg, h = 3 m

G PE KE
 

90 J











0 J

 

 

H?

 

 

H Never gets there! Doesn't have the energy to go any higher than G

 

 

 

 

Physics of Designing Rollercoasters

At what minimum

height should you place

the ball so it makes it all

the way around the loop?

UC Irvine

School blocks YouTube? Use the files below.

| LoopTheLoop.mov |LoopTheLoop.mpg |

 

 

 

 

The ball has to be

placed at a height above

the top of the loop so it

has the KE to continue.

 

 

 

 

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