DAY 23

#Goals: SWBAT...

1. Describe the relationship between inertia and mass

2. Match force names to their abbreviations and to their definitions

3. Define force and the unit of force

Warm-Up (5min)

Copy and fill in (or choose) the correct answers for the following:

• 1. Inertia: the resistance an object has to ______________
• 2. The more inertia that an object has, the more _____ it has.
• 3. A more massive object has a (greater/lesser) tendency to resist changes in its state of motion.
• 4. What is the meaning of "net" in relation to forces?
• 5. A net external force equal to zero means the forces are (balanced/unbalanced)
• 6. The presence of a net external force means that the object will be (accelerating/at rest)

CLASSWORK

1. #023A: What is a force?

• Force: Sometimes defined as a push or a pull on an object. Better Definition: A force is the ability to cause a change in state of motion of an object.
• Unit: Force is a quantity that is measured using the standard metric unit known as the Newton. A Newton is abbreviated by an "N." To say "10.0 N" means 10.0 Newton of force. One Newton is the amount of force required to give a 1-kg mass an acceleration of 1 m/s/s. Thus, the following unit equivalency can be stated:
  • 1 Newton = 1 kg • m/s2
• Is force a vector?

2. #023B: Force Types and their Classifications

What are the classifications of force?

Take 2 minutes to review Mr. P´s notes, go here ---> LINK

Make a four column chart (see example on board)

Using your knowledge, and the notes above, match the symbols/names of the forces with their definitions, then define each for as a ¨contact force¨ or an ¨action-at-a-distance/field¨ force

Definitions:

1. The force exerted by a compressed or stretched spring upon any object that is attached to it.

2. A force that is applied to an object by a person or another object.

3. The force exerted by a surface as an object moves across it or makes an effort to move across it.

4. A special type of frictional force that acts upon objects as they travel through the vacuum you can breathe. This force is often observed to oppose the motion of an object.

5. The force of gravity is the force with which the earth, moon, or other massively large object attracts another object towards itself.(aka weight)

6. the force that is transmitted through a string, rope, cable or wire when it is pulled tight by forces acting from opposite ends

7. The support force exerted upon an object that is in contact with another stable object

Symbols/Names:

Applied Force F_a

Gravitational Force F_g

Normal Force F_N

Force of Friction F_f

Air Resistance F_air

Tension Force F_tension

Spring Force F_spring

Stuck?

Help is here ---> LINK

3. #023C: Force Scenarios

Which forces are being applied here? What are the two objects exerting/feeling the force?

• A. The dog pulls on the leash.
• B. The hammer hits the nail.
• C. I fall out of a tree toward the Earth
• D. The car slides to a stop.

4. #023D: Are Mass and Weight the Same?

• What do you think?
• Mass is how much ______ is in an object. In science, we call that stuff _____
• Weight is the _____ of _______ upon that stuff.
• Which is a force, weight or mass?

5. #023E: Practice Questions

LINK Answer 1 & 2 (complete outside of class if necessary - I'm here at lunch/nutrition for help)

At Home Learning (HW)

1. Bring your lab materials (pre-lab, data, rough draft) and test study guide to class tomorrow

2. If you didn't complete 23D or 23E, complete them for tomorrow

3. #023F:

Take Notes: LINK 1

Watch the video, and answer the EdPuzzle Questions: LINK 2