2.4 levers

Question 1

define lever

Answer 1

a rigid structure that rotates about a fixed point when force is applied

Question 2

fulcrum

Answer 2

the point at which a lever rests or is supported; pivot point

Question 3

effort

Answer 3

applied force

Question 4

load

Answer 4

output force (resistance)

Question 4

resistance arm

Answer 4

distance between load and fulcrum

Question 5

effort arm

Answer 5

distance between effort and fulcrum

Question 6

1st class lever

Answer 6

the fulcrum lies between the effort and the load

Question 7

2nd class lever

Answer 7

fulcrum lies at one end with the effort at the other end and the load 8is in the middle; the load arm is smaller than the effort arm

Question 8

3rd class lever

Answer 8

effort lies between the load and the fulcrum; the effort arm is smaller than the load arm

Question 9

describe the mechanical advantage of using a 2nd class lever

Answer 9

MA is greater than 1, so larder loads can be moved with less effort

Question 10

describe the mechanical advantage of using a 3rd class lever

Answer 10

MA is less than 1, which means more effort is needed to move smaller loads

Question 11

describe which body parts become parts of a lever and how levers are used in the body

Answer 11

fulcrum - joints
effort - muscles
load - resistance, gravity, weight

Question 12

mechanical advantage

Answer 12

how much the effort force is multiplied by to overcome the load
any MA greater than 1.0 is considered very efficient