lever systems

Question 1

what is the lever, effort, load and fulcrum

Answer 1

• bone
• muscular force
• weight or resistance
• joint

Question 2

what are the main function of levers

Answer 2

• To generate muscular effort to overcome a given load
• To increase the speed of a given movement

Question 3

what is a 1st class lever + examples

Answer 3

E-F-L or L-F-E

E.g. extension of neck preparing to head a ball - football
E.g. tricep extensions/throwing an object/tennis serve/cricket bowl

Question 4

what is a 2nd class lever + example

Answer 4

E-L-F or F-L-E

E.g. ball of foot in take-off phase of a jump

Question 5

what is a 3rd class lever + examples

Answer 5

L-E-F or F-E-L

E.g. flexion of elbow during a bicep curl - bowls

Question 6

what is the efficiency of lever systems dependent on

Answer 6

• depends on the order + distance of the lever components from the fulcrum is important to their function
• the greater the distance of the effort or load from the fulcrum, the more significant the effort the load becomes

Question 7

what is the effort arm

Answer 7

the distance from the fulcrum to the effort

Question 8

what is the load arm

Answer 8

the distance from the load to the fulcrum

Question 9

mechanical advantage

Answer 9

• 2nd class lever system
• the effort arm is greater than the load arm
• effort arm>load arm
• a large load can be moved with relatively small effort
  e.g. take off phase in jump

Question 10

mechanical disadvantage

Answer 10

• 3rd class lever system
• load arm is greater than effort arm
• load arm>effort arm
• a large effort can be moved with relatively small load
  e.g. bicep curl