1. Mr. Finau Applied Science III

2. At what points of the flight of an object does it accelerate? How can you tell?  During all parts of its flight  The object constantly changes its velocity due to gravity

3. Light travels in a straight line at a constant speed of 3 X 10 8 m/s. What is its acceleration?  It has no acceleration…its speed is constant

4. Let’s assume this car drives off of the cliff with some velocity. Describe in detail what should happen to the car

5. What is the general path of all projectiles?  An arc or curve; a projectile will never travel in straight lines

6. Examples of Projectile Motion

7. If I throw a ball at an upward angle, why doesn’t it keep flying in that direction? Which direction is it pulled? What does it cause the ball to do?  Gravity causes it to fall  Pulled downward  Accelerates downward

8. At its peak, what is the vertical speed of the ball? What happens to its velocity?  The vertical speed is zero  The velocity changes vertical direction, but it continues with the same horizontal speed

9. Separation of Horizontal and Vertical Velocity Vertical Velocity Horizontal Velocity

10. If a bullet is fired horizontally from a gun and another bullet is dropped from the same height, which will hit the ground first?  Both will hit the ground at the same time  Everything falls at the same rate due to gravity

11. If there was no air resistance, will the horizontal velocity change? Would the horizontal speed be more or less if there WAS air resistance?  If there’s no air resistance, there’s nothing to slow it down in the horizontal direction  Air resistance is like friction caused when an object runs into air molecules  Speed would slow down, unless wind is blowing it faster

12.  Air resistance tends to slow an object’s velocity; it reduces the overall height and distance an object can travel What does air resistance do to the flight of a ball? w/o air resistanc e with air resistanc e

13. Why can a baseball travel farther than a tennis ball?  The baseball is denser than the tennis ball  This means that the baseball’s extra mass allows it to cut through the air resistance more easily

14. How can we describe projectile motion?  the motion of a particle through a region of space where it is subject to constant acceleration (gravity)

15. Describe the path of a projectile shot horizontally  The path still takes the form of an arc descending as gravity takes effect on the object

16. When an object is dropped from a flying plane, how does it fall?  The object maintains the horizontal speed of the plane and gains vertical speed from gravity  does not hit ground directly beneath original drop location  Has a curved path just like other projectiles