Movement

The neck is a __________

first class lever

What lever has resistance between the axis (fulcrum) and the force (effort)?

second

Explain the difference between mass and weight for objects on Earth and on the Moon.

Mass is a measure of an object's inertial force, or how much it resists motion, and of the amount of matter in it. Weight is the measure of gravity's pull on objects. Mass is independent of gravity, so the mass of an object will be the same on both Earth and the Moon. Because weight is dependent upon gravity, and the Earth has a greater force of gravity than the Moon, an object on the Earth will weigh more than it will on the Moon.

The ankle is a third class lever.

false

What tissue connects muscles to bones?

tendons

Which of the following is NOT a component of a lever?

tension

Second and third class levers both have __________

A. the fulcrum between the effort and load B.effort applied in the same place "incorrect" C.two loads and fulcrums D.the fulcrum at one end of the lever "correct"

What is the difference between velocity and acceleration?

Velocity is how fast an object moves and acceleration is the rate of change in velocity.

The first class lever is the most common lever in the human body.

false

The load is the pivot point of a lever.

false

To overcome an object's inertia, it must be acted upon by __________

force

What is kinetic energy?

the energy an object has due to its motion

The most common lever in the human body is the __________.

third class lever

Explain what distinguishes first class levers from second and third class levers.

First class levers have the fulcrum between the load and effort. This distinguishes first class levers from second and third class levers, where the load and effort are both on one side of the fulcrum.

What distinguishes the three different classes of levers found in the human body?

where the components of the lever are located

Explain why a seesaw is closest in arrangement to a first class lever.

Sample Response: The seesaw is a long lever arm with the load at one end, the effort at the opposite end, and the fulcrum in the center. With both the second and third class levers, however, the fulcrum is at one end of the lever and both the load and effort are on one side of the fulcrum. The seesaw is closest in arrangement to a first class lever because it is the only class of lever with the fulcrum between the load and effort.

Explain how Newton's law of inertia describes the motion of objects.

Sample: According to Newton's first law, the law of inertia, an object's velocity will not change unless it is acted upon by an outside force. This means that objects at rest tend to stay at rest, and objects in motion tend to stay in motion.

According to Newton's second law of motion, force is equal to mass times acceleration.

true

Swinging a tennis racket against a ball is an example of a third class lever.

true