Activities

1. Define evidence.
   
   
2. Define inference.

3. Present two claims that support the inference that simple machines simplify tasks.
   
   
4. Pick a simple machine and present evidence that supports the claim that simple machines make work easier.

5. Explain a scientific idea from prehistoric times that scientists are able to use evidence to support their inferences.
   
   
6. Explain how scientists use evidence to support inferences about extinct animal species.

Answer Key/Rubric

1. Evidence is collected facts and information that are used to prove or refute a theory.
   
   
2. An inference is an explanation made based on evidence or reasoning.
   
   
3. Acceptable responses may include, but are not limited to: Simple machines have the ability to transfer a force from one place to another, change the direction of a force, increase the magnitude of a force, or increase the distance or speed of a force.
   
   
4. Acceptable responses may include, but are not limited to:

• Wheel- transports objects, reduces friction and force needed to move an object
• Lever- lifts an object, reduced the amount of force needed to accomplish work
• Inclined plane- transports objects to a higher or lower elevation, reduces the amount of force needed to accomplish the change in elevation (though steeper angle requires more work)
• Pulley- lifts objects, increases distance traveled while decreasing force needed

5. Acceptable responses must include: reference of a prehistoric occurrence, what evidence exists to help support this inference

Sample answer: Scientists make inferences about dinosaurs and use evidence to support their theories since we are not able to study living dinosaurs. They can infer what they ate based on the shape of their teeth, or studying fossilized droppings. Scientists are also make inferences on their size, speed, and where they lived based on fossils of their bones.

6. Acceptable responses must include: presentation of evidence scientists have gathered that gives us insight on the extinct animals.

Sample Response: Scientists can examine skeletons to gain insight on the animal’s size and structure. Its foot and teeth shapes also give insight on the animal as well. Where the bones were found gives scientists information on where the animal lived. Based on the age of the rock layers in which the fossils were found, scientists make inferences about when the species lived, and when it may have become extinct.