1. Projectile motion Chapter 4, Section 4 Lecture 08 General Physics (PHYS101)

2. Projectile motion A projectile is an object that is thrown in air and moves only under the influence of Earth’s gravity. An object moves in both x and y directions simultaneously, so that we deal with a two dimensional motion. We will ignore air friction No acceleration in the horizontal direction The projectile’s acceleration is the free-fall acceleration

3. Equations of motion The horizontal motionThe vertical motion

4. Equation for the trajectory Parabola!

5. Projectile Motion: displacement At any time t, the projectile’s horizontal and vertical displacement: The magnitude of the displacement:

6. Projectile Motion: velocity

7. The maximum height of projectile The highest height which the object will reach is known as the peak of the object's motion. The increase of the height will last, until, that is, Time to reach the maximum height: From the vertical displacement of the maximum height of the object

8. The maximum distance of projectile From the horizontal displacement of the maximum distance of projectile: The horizontal range d of the projectile is the horizontal distance the projectile has travelled when it returns to its initial height (y=0). Time to reach the ground: Note that R has its maximum value when

9. Examples of projectile motion An object may be thrown horizontally The initial velocity is all in the x-direction All the general rules of projectile motion apply

10. Examples of projectile motion

11. Follow the general rules for projectile motion Break the y-direction into parts up and down symmetrical back to initial height and then the rest of the heigh

12. What do you think? 1. Hits the monkey regardless of the value of v 0. 2. Hits the monkey only if v 0 is large enough. 3. Misses the target. The downward acceleration of the bullet and the monkey are identical, so the bullet hit the target - they both fall the same distance.

14. Projectile motion vs free fall