agenda november 3, 2008

AGENDA November 3, 2008AGENDA November 3, 2008

Notes - Projectile MotionNotes - Projectile Motion CW - Plotting Projectile Motion Activity & go CW - Plotting Projectile Motion Activity & go

to to http://moourl.com/cyclops to play projectile play projectile motion Cyclops game!motion Cyclops game!

Projectile MotionProjectile Motion

Chapter 8Chapter 8

Mrs. PMrs. P


ProjectileProjectile – any object – any object projected by any means projected by any means that continues in motion.that continues in motion.

Determine what the Determine what the speedometer will read for speedometer will read for the free falling baseball the free falling baseball at time = 0, 1, 2, 3, 4 secat time = 0, 1, 2, 3, 4 sec


IF IF there were there were no gravityno gravity – any object thrown – any object thrown horizontally will continue horizontally will continue in a straight line path.in a straight line path.

BecauseBecause there there is gravityis gravity projectiles follow a projectiles follow a curved path called a curved path called a parabolaparabola..

Parabolic PathParabolic Path

A ball is thrown horizontally off the cliff.A ball is thrown horizontally off the cliff. Forces acting on the ballForces acting on the ball

Constant horizontal motionConstant horizontal motion Accelerated vertical motionAccelerated vertical motion

The combination of the two The combination of the two independent forces causes projectiles independent forces causes projectiles to follow a to follow a parabolicparabolic path. path.

Parabolic PathParabolic Path

Two component ForcesTwo component Forces Vertical (gravity)Vertical (gravity) Horizontal (throw - constant)Horizontal (throw - constant)

So Far We Know…So Far We Know…

a projectile is any object upon which a projectile is any object upon which the only constant force is gravity, the only constant force is gravity,

projectiles travel with a parabolic projectiles travel with a parabolic trajectory due to the influence of trajectory due to the influence of gravity, gravity,

So Far We Know…So Far We Know… there are no horizontal forces acting upon there are no horizontal forces acting upon

projectiles and thus no horizontal projectiles and thus no horizontal acceleration, acceleration,

the horizontal velocity of a projectile is the horizontal velocity of a projectile is constant (never changing in value), constant (never changing in value),

there is a vertical acceleration caused by there is a vertical acceleration caused by gravity; its value is ~10 m/sgravity; its value is ~10 m/s22, down, , down,

the vertical velocity of a projectile changes the vertical velocity of a projectile changes by ~10 m/s each second, by ~10 m/s each second,

the horizontal motion of a projectile is the horizontal motion of a projectile is independent of its vertical motion. independent of its vertical motion.

Vector DiagramsVector Diagrams

represent how the represent how the x- and y-x- and y-components of the components of the velocity change velocity change with timewith time

length of the length of the vector arrows are vector arrows are representative of representative of the magnitudes of the magnitudes of that quantity that quantity Note: Horizontal vector DOES NOT CHANGE!

Calculating DisplacementCalculating Displacement

Vertical Vertical DisplacementDisplacement

y = 0.5*g*ty = 0.5*g*t22

Horizontal Horizontal DisplacementDisplacement

x = vx = vixix * t * t

Calculating DisplacementCalculating Displacement Anna drops a ball from rest from the top of Anna drops a ball from rest from the top of

80-meter high cliff. How much time will it 80-meter high cliff. How much time will it take for the ball to reach the ground and at take for the ball to reach the ground and at what height will the ball be after each what height will the ball be after each second of motion? second of motion?

A cannonball is launched horizontally from A cannonball is launched horizontally from the top of an 80-meter high cliff. How the top of an 80-meter high cliff. How much time will it take for the ball to reach much time will it take for the ball to reach the ground and at what height will the ball the ground and at what height will the ball be after each second of travel? be after each second of travel?

AGENDA 6-NOV:AGENDA 6-NOV:

Projectile Motion LabProjectile Motion Lab

HW – HW – Part 2: Projectile Motion LabPart 2: Projectile Motion Lab TEST IN ONE WEEK TEST IN ONE WEEK


Submit HWSubmit HW No notesNo notes CW- The Influence of Gravity on CW- The Influence of Gravity on

distance traveled & Projectile distance traveled & Projectile motion challenge problemsmotion challenge problems

HW – HW – p 130 #1-6, Review, #1-3 Exercisesp 130 #1-6, Review, #1-3 Exercises Test Friday!Test Friday!


Submit HWSubmit HW

Notes – Gravity and SatellitesNotes – Gravity and Satellites

CW- The Force of Gravity & Exploration CW- The Force of Gravity & Exploration WS (if time)WS (if time)

HW – HW – p 130 #11, 13, 18 Review, p 113 #2, 5, 11 & p 130 #11, 13, 18 Review, p 113 #2, 5, 11 & TEST TUESDAY!TEST TUESDAY!

Terms to know:Terms to know:

TangentTangent – a line that touches – a line that touches a circular surface at only one a circular surface at only one point.point.

Tangential VelocityTangential Velocity – velocity – velocity whose direction is tangential whose direction is tangential to the Earth’s surface (parallel to the Earth’s surface (parallel or in the x-direction).or in the x-direction).

SatelliteSatellite – object with v – object with vxx = 8 = 8 km/s. Trajectory follows km/s. Trajectory follows curvature of the Earth’s curvature of the Earth’s surfacesurface

Newton’s Experiment:Newton’s Experiment:

cannonball launched from cannonball launched from an elevation > Earth’s an elevation > Earth’s atmosphere.atmosphere.

velocityvelocityxx is GREAT & is GREAT & trajectory becomes a circle.trajectory becomes a circle.

Air resistance minimal, Air resistance minimal, velocityvelocityxx remains the same remains the same

Object orbits Earth Object orbits Earth indefinitelyindefinitely

More Terms to know:More Terms to know:

EllipseEllipse – an oval-like path. – an oval-like path. Elliptical orbitElliptical orbit – an orbit – an orbit

followed by a projectile with a followed by a projectile with a velocity-x greater than 8 km/s. velocity-x greater than 8 km/s. Speed of an object decreases as Speed of an object decreases as it travels away from Earth and it travels away from Earth and increases as it comes near.increases as it comes near.

Escape speedEscape speed – the speed at – the speed at which a projectile can out run which a projectile can out run the force of gravity (11.1 km/s)the force of gravity (11.1 km/s)

Newton’s Discovery:Newton’s Discovery:

The Law of Universal GravitationThe Law of Universal Gravitation Gravity acts between all thingsGravity acts between all things Dependent on Mass and DistanceDependent on Mass and Distance

Force of gravity INVERSELY proportional to Force of gravity INVERSELY proportional to the square of the distance between them.the square of the distance between them.

F = [ G x (mF = [ G x (m11mm22) ] ÷ (d) ] ÷ (d22))

Constant = G = 6.67 x 10Constant = G = 6.67 x 10-11-11 Nm Nm22/kg/kg22

Some ?’s for you:Some ?’s for you:

If the tangential velocity of the moon were If the tangential velocity of the moon were zero, how would the moon move?zero, how would the moon move?

What happens to the force of gravity What happens to the force of gravity between two objects when the mass of between two objects when the mass of one body is doubled?one body is doubled?

How does the force of gravity between the How does the force of gravity between the earth and a rocket change as the distance earth and a rocket change as the distance between them is doubled?between them is doubled?


What other word do we use to describe the What other word do we use to describe the quantity achieved when mquantity achieved when m11 is your mass, is your mass, mm22 is the Earth’s mass, and d is the earth’s is the Earth’s mass, and d is the earth’s radius?radius?

What must be true in order for a satellite What must be true in order for a satellite to stay in orbit?to stay in orbit?


Notes – Gravity and Satellites

CW- Newton’s Law of Universal CW- Newton’s Law of Universal GravitationGravitation

HW – p 115 Problems #1-7 & 9 p HW – p 115 Problems #1-7 & 9 p 132 Problem #1132 Problem #1


Submit HWSubmit HW

ReviewReview

HW – STUDY! HW – STUDY!


CW – Review PacketCW – Review Packet

HW – Study!!! Test Tomorrow! PJAS HW – Study!!! Test Tomorrow! PJAS #5 Due 11/21!#5 Due 11/21!

AGENDA ?-JAN:AGENDA ?-JAN: Review big ideas in Projectile Motion & Review big ideas in Projectile Motion &

GravityGravity

CW – Projectile Motion ReviewCW – Projectile Motion Review

HWHW Finish Projectile Motion Review – STUDY!Finish Projectile Motion Review – STUDY! Organize BinderOrganize Binder QPA Thursday!!!!!QPA Thursday!!!!!


Describe for a projectile the Describe for a projectile the changes in the vertical and changes in the vertical and horizontal components of its horizontal components of its velocity.velocity.

Vertical component changes at a rate of Vertical component changes at a rate of (-) 9.8 m/s(-) 9.8 m/s22 due to gravity. due to gravity.

Horizontal component DOES NOT change. Horizontal component DOES NOT change.


Calculate time or distance Calculate time or distance traveled by an object in free-fall.traveled by an object in free-fall.

Vertical component use dVertical component use dyy = ½ a x t = ½ a x t22..

Horizontal component use dHorizontal component use dxx = v = vii x t x t


Show the connection between a fast-Show the connection between a fast-moving projectile and an Earth moving projectile and an Earth satellite. satellite.

cannonball launched from an elevation > cannonball launched from an elevation > Earth’s atmosphere.Earth’s atmosphere.

velocityvelocityxx is GREAT is GREAT trajectory becomes a circle.trajectory becomes a circle. Air resistance minimalAir resistance minimal velocityvelocityxx remains the same remains the same Object orbits Earth indefinitelyObject orbits Earth indefinitely


Describe how the speed of a Describe how the speed of a satellite changes for different satellite changes for different portions of an elliptical orbit.portions of an elliptical orbit. Circular orbit – constant speedCircular orbit – constant speed Elliptical orbit – changing speedElliptical orbit – changing speed

Describe what it is meant by Describe what it is meant by escape speed.escape speed. The horizontal speed at which an object The horizontal speed at which an object

will not become a satellitewill not become a satellite

GravityGravity

State Newton’s law of universal State Newton’s law of universal gravitation.gravitation.

Gravity acts between all thingsGravity acts between all things Dependent on Mass and DistanceDependent on Mass and Distance

F = [ G x (mF = [ G x (m11mm22) ] ÷ (d) ] ÷ (d22))

Constant = G = 6.67 x 10Constant = G = 6.67 x 10-11-11 Nm Nm22/kg/kg22


Describe the how the force of Describe the how the force of gravity changes with … gravity changes with …

Distance – as distance increases, force Distance – as distance increases, force decreases by change in distance decreases by change in distance squared! INVERSE RELATIONSHIPsquared! INVERSE RELATIONSHIP

Mass – as mass increases, force changes Mass – as mass increases, force changes directly by change in mass of object(s).directly by change in mass of object(s).


If the tangential velocity of the moon were If the tangential velocity of the moon were zero, how would the moon move?zero, how would the moon move?

What happens to the force of gravity What happens to the force of gravity between two objects when the mass of between two objects when the mass of one body is doubled?one body is doubled?

How does the force of gravity between the How does the force of gravity between the earth and a rocket change as the distance earth and a rocket change as the distance between them is doubled?between them is doubled?


What other word do we use to describe the What other word do we use to describe the quantity achieved when mquantity achieved when m11 is your mass, is your mass, mm22 is the Earth’s mass, and d is the earth’s is the Earth’s mass, and d is the earth’s radius?radius?

What must be true in order for a satellite What must be true in order for a satellite to stay in orbit?to stay in orbit?

agenda november 3, 2008

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