Projectile MotionProjectile Motion

By:By:

Mujahed KhanMujahed Khan

Eman NaderEman Nader

Lorenz SchuerchLorenz Schuerch

TermsTerms Projectile- is an object upon which the only force acting Projectile- is an object upon which the only force acting

is gravity, it is any object which once projected is gravity, it is any object which once projected continues in motion by its own inertia and is influenced continues in motion by its own inertia and is influenced only by the downward force of gravity.only by the downward force of gravity.

Parabola-a plane curve formed by the intersection of a Parabola-a plane curve formed by the intersection of a right circular cone and a plane parallel to an element of right circular cone and a plane parallel to an element of the curvethe curve

Concept Concept

The concept of a projectile motion is that an The concept of a projectile motion is that an object an that follows moving in constant object an that follows moving in constant horizontal velocity and also drops due to the horizontal velocity and also drops due to the force of gravity, just like free fall except it force of gravity, just like free fall except it does not immediately hit the ground when it does not immediately hit the ground when it is released.is released.

Examples of ProjectileExamples of Projectile

The Laws of Projectile ProblemsThe Laws of Projectile Problems1.Draw a picture1.Draw a picture

2. Write givens in terms of x and y2. Write givens in terms of x and y

3. Decide what to solve for3. Decide what to solve for

4. In horizontal use V=d/t 4. In horizontal use V=d/t

5. In vertical use d=vit+1/2atsquared or 2ad=Vfsquared –Visquared5. In vertical use d=vit+1/2atsquared or 2ad=Vfsquared –Visquared

6. If problem is horizontal vi=om/s in vertical6. If problem is horizontal vi=om/s in vertical

7. If problem relates to an angle, use SOHCAHTOA 7. If problem relates to an angle, use SOHCAHTOA

8. If problem dt, vf at top of path=0m/s8. If problem dt, vf at top of path=0m/s

9. A=-9.8 m/s in vertical9. A=-9.8 m/s in vertical

10. Solve your problem10. Solve your problem

Sample ProblemsSample Problems

1.1. If you drop a water balloon from a 5 If you drop a water balloon from a 5 meter tall ledge. How long does the meter tall ledge. How long does the balloon take to reach the ground?balloon take to reach the ground?

Equation: d=vit+½atsquaredEquation: d=vit+½atsquared

acceleration=-9.8acceleration=-9.8

initial velocity= 0m/sinitial velocity= 0m/s

distance=5mdistance=5m

time=?time=?

5m=(0m/s)+½(-9.8)(tsquared)5m=(0m/s)+½(-9.8)(tsquared)

½(-9.8)=-4.9½(-9.8)=-4.9

5/-4.9=-4.9tsquared/-4.95/-4.9=-4.9tsquared/-4.9

Time= 1 SecondTime= 1 Second

2. A potato is shot horizontally out of a 2. A potato is shot horizontally out of a cannon with a speed of 60m/s at a cannon with a speed of 60m/s at a target 70m away. How long does target 70m away. How long does the potato take to travel the the potato take to travel the horizontal distance?horizontal distance?

Equation: Velocity=distance/timeEquation: Velocity=distance/time

Velocity=60m/sVelocity=60m/s

distance=70m/sdistance=70m/s

time=?time=?

60=70/t60=70/t

time=1.16 secondstime=1.16 seconds

70m

60m

Quiz QuestionsQuiz Questions1.1. Lorenz wants to ride his bicycle at 10 m/s at heading 40 Lorenz wants to ride his bicycle at 10 m/s at heading 40

degrees NE. How much of his velocity is north and how much degrees NE. How much of his velocity is north and how much is east?is east?

2.2. A bullet is fired horizontally at a target 50 meters away, and it A bullet is fired horizontally at a target 50 meters away, and it has dropped 0.5 meters by the time it reaches the target, how has dropped 0.5 meters by the time it reaches the target, how long does it take to drop?long does it take to drop?

3.3. Eman decides to jump of a cliff, she jumps horizontally at Eman decides to jump of a cliff, she jumps horizontally at 3m/s from a 25 meter tall cliff. Below her, rocks extend form 3m/s from a 25 meter tall cliff. Below her, rocks extend form the base of the cliff for 5 meters. Will the she clear the rocks?the base of the cliff for 5 meters. Will the she clear the rocks?

4.4. If you drop a ball from rest what information do you need to If you drop a ball from rest what information do you need to predict how time it will take to hit the floor?predict how time it will take to hit the floor?

AnswersAnswers

1. horizontal velocity is 6.43m/s and vertical 1. horizontal velocity is 6.43m/s and vertical velocity is 7.7m/svelocity is 7.7m/s

2. time is .32seconds2. time is .32seconds

3. Yes she will clear the rocks3. Yes she will clear the rocks

4. You need Distance,Acceleration, Initial 4. You need Distance,Acceleration, Initial Velocity, and Time Velocity, and Time