Lever systems

Question 1

how does a lever work?

Answer 1

fulcrum - your joint
load - the actual thing you want to move (eg. dumbbell)
effort - this is supplied by your muscles

Question 2

different classes of lever:

Answer 2

-first class
-second class
-third class

Question 3

first class lever

Answer 3

-effort of the left (down)
-fulcrum in the middle
-load soon the right

eg. elbow triceps or tricep dips

Question 4

second class lever

Answer 4

-fulcrum at the left
-load in the middle
-effort of the right (up)

eg. calf raise

Question 5

third class lever

Answer 5

-fulcrum at the left
-effort in the middle (up)
-load at the right

eg. bicep curl

Question 6

why does your body have levers?

Answer 6

• mechanical advantage
  -mechanical disadvantage

Question 7

mechanical advantage

Answer 7

-happens when the output of the lever is greater than the input (when the load is greater than the effort)
-you are getting more out than you are putting in

to calculate advantage:
input divided by output

Question 8

mechanical disadvantage

Answer 8

-when the effort and load are on the same side of the fulcrum (but the effort sits closer tot he fulcrum than the load does)
-the input of the lever is greater than the output
-the force you apply is greater than the load
-you are putting in more than you are getting out

Question 9

advantages and disadvantages of first class lever:

Answer 9

advantages:
-stable
-strong
-increasing length of lever arm, increases mechanical advantage

disadvantages:
-flow
-limited flexibility

Question 10

advantages and disadvantages of second class levers:

Answer 10

advantages:
-stable
-strong
-increasing the length of the lever arm, increases the mechanical advantage

disadvantages:
-slow
-limited flexibility

Question 11

advantages and disadvantages of third class levers:

Answer 11

-fast movement
-large range of motion
-increasing the length of the lever arm decreases the mechanical advantage

-force applied must always exceed the load