1. The two factors that affect the friction force between two surfaces are the types of surfaces in contact and the force pressing the surfaces together.
2. One way you could reduce the friction between two surfaces is by using a lubricant, such as oil or grease, between them. This is because the lubricant creates a thin layer that separates the surfaces, reducing direct contact and allowing them to slide more easily. Some objects fall through the air at a different rate than others because of air resistance, which depends on the object's shape, size, and speed. Objects with larger surface areas or more aerodynamic shapes experience more air resistance, which can slow their fall.
3. Two factors that affect the gravitational force between two objects are the masses of the objects and the distance between them. The greater the masses, the stronger the gravitational force; the greater the distance, the weaker the gravitational force.
Matching:
6. friction - f. the kind of friction that results when you rub sandpaper against wood
7. rolling friction - d. the kind of friction that slows a rolling object
8. sliding friction - e. the kind that exists when the only surface acting on an object is gravity
9. fluid friction - g. the kind of friction that results when a wheel turns on a surface
10. weight - b. the kind of friction that exists between oil and a door hinge
11. free fall - c. the general term for the force that not surface exerts on another when they rub against each other
12. gravity - a. the force that accelerates objects towards Earth
13. terminal velocity - h. a measurement of the force of gravity on an object
14. air resistance - i. a falling object reaches this when forces of gravity and air resistance are balanced
Parent Tip: Review the logic above to help your child master the concept of friction worksheet middle school.
