BIOLOGY - 7 RBW CHAP 9

scissors are an example of which class of lever?

• first-class

• secong-class

• third-class

• fourth-class

what is the purpose of simple machines?

• to make work harder

• to make work easier

• to create energy

• to create work

what is an example of a second-class lever

• the knee

• the elbow

• the ankle

• the pelvis

mechanical advantage is the ratio of the resistance force divided by what?

• resistance distance

• work

• effort distance

• effort force

what connects bone to muscle?

• cartilage

• tendons

• ligaments

• collagen

what is another job of the skeletal system, besides support?

• to conduct nerve impulses

• to protect internal organs

• to clean blood

• to contract

what is the opposite of flexion?

• extension

• contraction

• hinge joint

• mechanical advantage

what types of joints are in the skull?

• ball-and-socket

• hinge

• saddle

• immovable

the elbow joint is a fulcrum for which class of lever?

• first-class

• second-class

• third-class

• all classes

what does a mechanical advantage greater than one usually mean?

• resistance is greater

• heavy objects can be lifted

• only light objects can be lifted

• input force is very high