Projectile Motion By: Mujahed Khan Eman Nader Lorenz Schuerch Terms Projectile- is an object upon which the only force acting is gravity, it is any object which once projected continues in motion by its own inertia and is influenced only by the downward force of gravity. Parabola-a plane curve formed by the intersection of a right circular cone and a plane parallel to an element of the curve Concept The concept of a projectile motion is that an object an that follows moving in constant horizontal velocity and also drops due to the force of gravity, just like free fall except it does not immediately hit the ground when it is released. Examples of Projectile The Laws of Projectile Problems 1.Draw a picture 2. Write givens in terms of x and y 3. Decide what to solve for 4. In horizontal use V=d/t 5. In vertical use d=vit+1/2atsquared or 2ad=Vfsquared –Visquared 6. If problem is horizontal vi=om/s in vertical 7. If problem relates to an angle, use SOHCAHTOA 8. If problem dt, vf at top of path=0m/s 9. A=-9.8 m/s in vertical 10. Solve your problem Sample Problems If you drop a water balloon from a 5 meter tall ledge. How long does the balloon take to reach the ground? Equation: d=vit+½atsquared acceleration=-9.8 initial velocity= 0m/s distance=5m time=? 5m=(0m/s)+½(-9.8)(tsquared) ½(-9.8)=-4.9 5/-4.9=-4.9tsquared/-4.9 Time= 1 Second 1. 2. A potato is shot horizontally out of a cannon with a speed of 60m/s at a target 70m away. How long does the potato take to travel the horizontal distance? Equation: Velocity=distance/time Velocity=60m/s 60m distance=70m/s time=? 60=70/t 70m time=1.16 seconds Quiz Questions 1. 2. 3. 4. 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 is east? 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 long does it take to drop? Eman decides to jump of a cliff, she jumps horizontally at 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? If you drop a ball from rest what information do you need to predict how time it will take to hit the floor? Answers 1. horizontal velocity is 6.43m/s and vertical velocity is 7.7m/s 2. time is .32seconds 3. Yes she will clear the rocks 4. You need Distance,Acceleration, Initial Velocity, and Time