Monday November 28, 2011Warm Up

Write down the most exciting thing you did

over Thanksgiving Break

Classwork

# 37 Gravity & Motion Notes#38 Gravity Questions to Ponder

Homework

Complete #38

#37 Gravity & Motion Notes

• Velocity changes 9.8 meters per second due to gravitational force.

1s 9.8 m/s 2s 19.6 m/s

3s 29.4 m/s

• You can calculate the velocity of a falling object using the formula

v = g ● t g= acceleration due to gravity t= fall time

• EX: What is the velocity of the soccer ball when it falls for 3 seconds?

v = 9.8m/s2 ● 3 s v = 29.4 m/s

• All objects should fall at the same rate, but air resistance makes this not happen

• Air resistance is the force that opposes motion of falling objects through air– Amount of air resistance depends on size, shape and speed

• Terminal Velocity is when the force of gravity equals the force of air resistance – Acceleration stops at terminal velocity and you fall at a constant velocity

http://waowen.screaming.net/revision/force&motion/skydiver.htm

• Free Fall – when the only force acting on an object is gravity– Not possible on earth

Air Resistance

GravityForce of gravity is larger than air resistance so acceleration is occuring Air Resistance

GravityBalanced force between gravity and air resistanceNo acceleration = terminal velocity

Sky Diving Adventure!

#38 Gravity Questions to Ponder

• Which item would fall more quickly to the ground, an acorn or a leaf? Explain why?

• If gravity is the same for all objects on Earth, why don’t all objects fall at the same speed?

• What is terminal velocity? Is it a good thing or a bad thing?

• Why does free fall not really exist on Earth?

Tuesday November 29, 2011Warm Up

What is an unbalanced force?

a. Any force acting on an object

b. A force that changes the motion of an object

c. A force that stops an object ONLY

d. A force that moves an object ONLY

Classwork

# 39 Orbiting and Projectile Motion#40 Gravity & Projectile Motion Practice

Homework

Complete #40

#39 Orbiting and Projectile Motion• Free fall – when the ONLY force acting on an object is gravity.

– In all cases on earth there is no free fall b/c of air resistance– Where in the universe is gravity the only force?

• Free Fall in SPACE causes orbiting

How orbiting works: 1. The planet has inertia, itWants to continue in the same direction2. Gravity pulls the planet toward the sun3. The planet keeps trying to continue With its inertia, but gravity pulls Creating an orbit

Planet’s inertia

• Projectile Motion- the curved path an object follows when it is thrown near the surface of the Earth– 2 parts : vertical motion, horizontal motion

– The horizontal motion is from you throwing the ball– Horizontal motion is parallel to the ground &

remains constant once it leaves your hand

– The vertical motion is perpendicular to the ground. – Once the ball leaves your hand gravity can pull the

object 9.8m/s2 toward the ground

How does vertical and horizontal motion create a curved path?

#40 Gravity & Projectile Motion Practice

• Textbook pg 157 # 2-6• Describe 3 situations where projectile motion

occurs. Illustrate and identify the cause of the vertical and horizontal motion in 1 of your situations

Wednesday November 30, 2011Warm Up

Which of the following situations shows projectile motion?

a. A penny falling off a building

b. A frog jumping from lilly pad to lilly pad

c. A baseball being thrownd. Both b & c show projectile

motion

Classwork

#41 Newton’s 1st Law #42 NFL & Newton’s 1st Law

Homework

Complete #42

Newton’s 1st Laws Notes

Read pg 158 – 160 to answer the following questions on #41 in Albert

1. What is Newtons 1st law of motion?2. What is part 1 of Newton’s law? 3. What is part 2 of Newton’s law? 4. What is an unbalanced force? *you may have to look

back in your notes*5. Why doesn’t a softball continue rolling forever when

hit into the outfield?6. How is friction related to Newton’s 1st law of motion?7. What is inertia?8. How is inertia related to Newton’s 1st law?9. How are mass and inertia related?

#42 NFL & Newton’s 1ST Lawhttp://science360.gov/obj/video/70fadaa8-c3d4-4132-ba1f-c98be5caeb14

1. Rewrite Newton’s 1st law in the context of football 2. How does a defender act as an unbalanced force?3. What is a players resistance to an unbalanced force?4. How does inertia make an offensive player difficult

to tackle5. Describe the difference between mass and weight6. How does mass effect inertia?

Thursday December 1, 2011Warm Up

Newtons 1st law applies to

a. Moving objectsb. Objects that are not

movingc. Objects that are

acceleratingd. Both (a) and (b)

Classwork

# 43 Inertia-Rama#44 Inertia-Rama Conclusion

Homework

Complete #44

#43 Inertia-Rama!!!Predict & Discover

Activity What you think will happen What happened and why

Table cloth magic trick- Pull a table cloth out from under cups of water

Coin Shoot - Shoot a coin at a stack of 11 coins

Drop a ball at a target while you are running by