Question

1. which of the following objects is correctly matched with a type of joint that performs a similar movement?

○ a shower head, which is similar to a hinge joint
○ a cabinet door, which is similar to a pivotal joint
○ a doorknob, which is similar to a pivot joint
○ a swivel chair, which is similar to a hinge joint

Explanation:

• A hinge joint allows movement in one plane (like a door opening/closing). A shower head moves more freely than a simple hinge - like movement. A cabinet door uses a hinge - like movement (not a pivotal joint which has a different movement pattern). A swivel chair has a rotational movement around a central axis (more like a ball and socket in some ways but not a hinge). A doorknob rotates around a central axis (similar to a pivot joint which allows rotational movement around a single axis).

Answer:

a doorknob, which is similar to a pivot joint