3.1.2 movement analysis - bexhill high academy 1 2 1 - lever systems a… · aqa gcse physical...

AQA GCSE Physical Education 3.1.2 – Movement Analysis

3.1.2 – MOVEMENT ANALYSIS 3.1.1.1 – Levers

Mechanical Advantage

Wednesday, 28 February 2018


starter 1. Stick in your Assessment

Grids from last lesson. NOT FOLDED

2. Fill out the score underneath the “start” of the lesson

3. Correct any missing/incorrect answers in green pen


Start = %

End = %


Learning objectives

• To be able to explain the mechanical advantage

of each lever and related movements.

• To understand the 3 different lever class systems



Whiteboards


• Using the whiteboards you have been

provided you need to answer the

questions.

• When you have written your answer put

your pen down and wait for the

instruction to show.


1.

Draw a linear diagram of a 1st Class Lever

System


Effort

Lever Arm

Load

Fulcrum


2.

Draw a linear diagram of a 2nd Class Lever

System


Fulcrum

Lever Arm

Load

Effort


3.

Draw a linear diagram of a 3rd Class Lever

System


Fulcrum Effort

Lever Arm

Load


4.

Which lever system is being used in picture

below?



5.


below?


http://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiF8o3cjKnRAhVMWxQKHdhnApgQjRwIBw&url=http://www.humankinetics.com/excerpts/excerpts/levers-work-to-create-movement-in-the-human-body&psig=AFQjCNHPKJXRa3MQwUc6v-TY_VzXvibdkA&ust=1483640174663727


6.


below?



Mechanical advantage

The relative efficiency of each of the lever systems

is called the ‘mechanical advantage’.


Fulcrum

Effort

Lever Arm

Load

How can the 1st class lever below be adjusted to increase or change how high the load can be propelled?



The efficiency of a working lever, calculated by:

effort ÷ weight (resistance) arm




The body‟s levers can be made even more

effective by using rackets, oars, paddles, sticks

and bats.




These pieces of equipment increase the length of

the resistance arm of the lever. This in turn

increases the speed at the end of the lever.



Effects of a lever on the human body

The extent to which a lever can increase speed

depends upon the relative lengths of the

resistance arm (RA) and effort arm (EA).


Fulcrum

Effort

Lever Arm

Load

Resistance

Arm (RA)

Effort Arm

(EA)

RA - Part of

the lever

between the

fulcrum & the

load

EA – Part

of the lever

between

the fulcrum

& the effort


Resistance arm

The resistance arm (RA) is the part of the lever

between the fulcrum and the resistance.

The longer the resistance arm, the greater speed

can be generated.


Resistance

Arm (RA)

Fulcrum

Effort

Lever Arm

Load


Effort arm

The effort arm (EA) is the distance between the

fulcrum and the effort; the longer the effort arm the

more force can be generated


Effort Arm

(EA)

Fulcrum

Effort

Lever Arm

Load

Sporting implements are often used

such as rackets or bats to increase

the length of the effort arm which will

increase the force that an object such

as a ball is struck.


Effort arm However the optimal length of an implement should be

determined by the strength of the person handling.

e.g. junior tennis rackets have been designed for this

purpose.



Mechanical disadvantage

Most levers in the body are third class levers

where the resistance arm is always greater than

the effort arm (mechanical disadvantage).

The longer the resistance arm of the lever, the

greater the speed at the end of it.


So when bowling or passing a

ball the performers arm should

be fully extended to generate

the most force and with the

greatest speed.


Exam questions and resources



Label the following levers components.

Describe the 3 levers in the body (use diagrams to help

illustrate your answer)

Explain the term „mechanical advantage‟

Which class of lever always has a mechanical

disadvantage?

Levers and mechanical advantage

Apply it! What has stuck with you?


Exam questions

1. Which one of the following describes a second class lever system?

(1)

A The load is at the right-hand end of the lever

B The fulcrum is in the middle of the lever

C The load is in the middle of the lever

D The load and the fulcrum are at the same point on the lever

2. Label the lever system below (4)

Lever class = _______________________

Practice it!

___________

___________

___________


Exam questions

3. Which one of these shows how to calculate the

mechanical advantage of a lever?

(1)

A Effort arm x weight (resistance) arm

B Effort arm † weight (resistance) arm

C Effort arm + weight (resistance) arm

D Effort arm - weight (resistance) arm

Practice it!


Exam questions

4. Analyse how the following parts of the lever system

allow the weight trainer in Figure 5 to lift the weight.

Practice it!

(i) Fulcrum (2)

(ii) Effort (2)


Exam questions

5. Figure 4 shows a basketball player jumping to execute a

shot. Draw the lever system which operates at the ankle

joint in the space below. Label the fulcrum, effort and load.

(1)

Practice it!


Marks Scheme:

1. C

2. i) Third class lever

3. B

4. One mark for linking bone or muscle to component of

lever system and one mark for linking this to its use in

the biceps curl to lift the weight. For example:

Fulcrum – elbow is the fulcrum (1) which allows the

arm to bend/flex (1) Effort – biceps muscle provide

the effort (1) which allows the weight lifter to lift the

weight (1)

Practice it! Load

Effort

Fulcrum


Marks Scheme:

5. Award one mark for labelling the effort, load /

resistance and fulcrum in the correct order.

Practice it!

3.1.2 movement analysis - bexhill high academy 1 2 1 - lever systems a… · aqa gcse physical...

Documents