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Projectile Motion I

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WHAT IS

PROJECTILEMOTION?

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Defining Projectiles

A projectile is an object upon which the only forceacting is gravity. There are a variety of examples ofprojectiles. An object dropped from rest is a projectile(provided that the influence of air resistance is

negligible). An object that is thrown verticallyupward is also a projectile (provided that theinfluence of air resistance is negligible). And anobject which is thrown upward at an angle to thehorizontal is also a projectile (provided that theinfluence of air resistance is negligible).

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A projectile is any object that onceprojectedor

dropped continues in motion by its own inertiaand is influenced only by the downward forceof gravity.

The path of a projectile is called its trajectory.

http://www.physicsclassroom.com/Class/newtlaws/u2l1b.cfmhttp://www.physicsclassroom.com/Class/newtlaws/u2l1b.cfm

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Projectile Motion n! Inerti

Newtons laws suggest that forces are only re!uired to cause anacceleration (not a motion).

A force is not re!uired to "eep an object in motion. A force isonly re!uired to maintain an acceleration. And in the case of a

projectile that is moving upward# there is a downward force

and a downward acceleration. That is# the object is movingupward and slowing down.

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Now suppose that thegravity switchis turned onand that the cannonball is projected

horizontally from the top of the same cliff.$hat effect will gravity have upon the motionof the cannonball% $ill gravity affect the

cannonballs horizontal motion% $ill thecannonball travel a greater (or shorter)horizontal distance due to the influence of

gravity%

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A projectile is an object upon which the only force isgravity. &ravity acts to influence the vertical

motion of the projectile# thus causing a verticalacceleration. The horizontal motion of theprojectile is the result of the tendency of any object

in motion to remain in motion at constant velocity.'ue to the absence of horizontal forces# a projectileremains in motion with a constant horizontalvelocity. orizontal forces are not re!uired to "eep

a projectile moving horizontally. The only forceacting upon a projectile is gravity

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A projectile is any object with an initial non*

zero# horizontal velocity whose acceleration isdue to gravity alone.

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The "ey components that we need to remember in order to solveprojectile motion problems are+

,nitial launch angle# ,nitial velocity# u Time of flight# T Acceleration# a orizontal velocity# vx -ertical velocity# vy 'isplacement# d

aximum height#H /ange#R

https://www.boundless.com/definition/velocity/https://www.boundless.com/definition/acceleration/https://www.boundless.com/definition/acceleration/https://www.boundless.com/definition/velocity/

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trajectory formula

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Question 1:

A body is projected with a velocity of 01 ms*2 at 31oto the horizontal. 4ind(i) aximum height reached

(ii) Time of flight and(iii) /ange of the projectile.Solution:

,nitial -elocity -o5 01 ms*2#6 5 31o

Time of flight# t 5 0-1sin6g 5 07017sin3118.9 5 :.20; s.

aximum eight reached# 5 -0osin060g 5 (01)0sin0310078.9

5 22.8< m.

orizontal /ange / 5 v01sin06g 5 010sin211o8.9 5 =1.28; m.

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>ohn is on top of the building and jac" is down. ,f john throws a ball at anangle of ;1oand with initial velocity 01 m?s. At what height will the ballreach after 0 s%

Solution:&iven+ -yo5 01 m?s#

@ t 5 0s#The -ertical velocity in y direction is given by -y5 -yosin ;1o

5 01 7 :0

5 2

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Ballistic

The study of the motion ofprojectiles. is the science of mechanicsthat deals with the

launching# flight# behavior# and effects ofprojectiles# especiallybullets#gravitybombs#roc"ets# or the li"eB the science or art ofdesigning and accelerating projectiles so as to

achieve a desired performance.

http://scienceworld.wolfram.com/physics/Projectile.htmlhttp://en.wikipedia.org/wiki/Mechanicshttp://en.wikipedia.org/wiki/Flighthttp://en.wikipedia.org/wiki/Projectilehttp://en.wikipedia.org/wiki/Bullethttp://en.wikipedia.org/wiki/Gravity_bombhttp://en.wikipedia.org/wiki/Gravity_bombhttp://en.wikipedia.org/wiki/Rockethttp://en.wikipedia.org/wiki/Rockethttp://en.wikipedia.org/wiki/Gravity_bombhttp://en.wikipedia.org/wiki/Gravity_bombhttp://en.wikipedia.org/wiki/Bullethttp://en.wikipedia.org/wiki/Projectilehttp://en.wikipedia.org/wiki/Flighthttp://en.wikipedia.org/wiki/Mechanicshttp://scienceworld.wolfram.com/physics/Projectile.html