Explain what distinguishes first class levers from second and third class levers.
First-class levers have the fulcrum between the effort and the load. Second-class levers have the load between the fulcrum and effort, while third-class levers have the effort between the fulcrum and load.
Explain what is meant by the term mechanical advantage.
Mechanical advantage is the ratio of the force a machine produces to the effort force applied to it. It describes how much the machine multiplies force.
Explain how Newton's law of inertia describes the motion of objects.
Newton's law of inertia states that an object at rest stays at rest, and an object in motion continues moving at a constant speed and in a straight line, unless an unbalanced external force acts on it.
Explain how Newton's law of inertia describes the motion of objects.
Newton's law of inertia states that an object at rest stays at rest, and an object in motion continues moving in a straight line at a constant speed, unless acted on by a net external force. A net force is needed to change an object's speed or direction.
The most common lever in the human body is the __________.
What is kinetic energy?
To overcome an object's inertia, it must be acted upon by __________.
Explain why a seesaw is closest in arrangement to a first class lever.
A seesaw is closest to a first-class lever because its pivot, or fulcrum, is between the effort on one side and the load on the other. Moving one side down applies effort that lifts the other side.
What tissue connects muscles to bones?
Explain why a seesaw is closest in arrangement to a first class lever.
A seesaw is like a first-class lever because its fulcrum is positioned between the effort applied on one side and the load on the other side.
The most common lever in the human body is the __________.
Explain what is meant by the term mechanical advantage.
Mechanical advantage describes how much a machine multiplies an input force. It is the ratio of the force exerted by the machine (output force) to the force applied to it (input force).
The neck is a __________.
Explain what distinguishes first class levers from second and third class levers.
The classes differ in which part is positioned between the other two. In a first-class lever, the fulcrum is between the effort and the load. In a second-class lever, the load is between the fulcrum and the effort. In a third-class lever, the effort is between the fulcrum and the load.
Explain the difference between mass and weight for objects on Earth and on the Moon.
Mass is the amount of matter in an object and remains the same on Earth and on the Moon. Weight is the force of gravity on the object, so an object weighs about one-sixth as much on the Moon as it does on Earth.
Explain the difference between mass and weight for objects on Earth and on the Moon.
Mass is the amount of matter in an object and stays the same on Earth and on the Moon. Weight is the force of gravity acting on that mass. Because the Moon's gravity is weaker, an object weighs about one-sixth as much there as it does on Earth.
Did you find these answers helpful?