1. Vf vertical velocity
Monday, October 19, 2015

2. Monday, 10/19 Unit 3: Two dimensional motion
Respond to the following on your warm-up sheet
In the game modern warfare, you fire your M203 grenade horizontally from the roof of a building that is 11 meters tall. The grenade lands 114 meters from the base of your building. What is the initial horizontal velocity of your grenade?
Upcoming dates
Friday, 10/23 – quiz
Thursday, 10/29 – projectile motion project due
Thursday, 10/29 – unit 3 test
See my webpage for additional 2NW dates

3. Monday, 10/19 Unit 3: Two dimensional motion
Respond to the following on your warm-up sheet
In the game modern warfare, you fire your M203 grenade horizontally from the roof of a building that is 11 meters tall. The grenade lands 114 meters from the base of your building. What is the initial horizontal velocity of your grenade?

4. Horizontal Projectile
What we know
A projectile has two dimensions to it’s motion.
Horizontal
Vertical
The initial velocity (Vi) in the horizontal is a value that is given to us or we can calculate it.
The initial velocity (Vi) in the vertical is always zero.

5. Horizontal Projectile
What about Final Velocity?
Watch animation

6. Horizontal Projectile – Velocity
Horizontal Velocity
There is no force acting on the object horizontally therefore inertia applies and the horizontal velocity remains constant.
There is no change in velocity therefore there is no acceleration.
What do you think the final horizontal velocity would be just before it hits the ground?

7. Horizontal Projectile – Velocity
Vertical Velocity
When the projectile is launched there is no initial vertical velocity.
After the projectile is launched the force of gravity starts to have an affect on the vertical motion of the object.
The objects starts to accelerate (velocity is changing).
The velocity starts to increase.
What do you think the final vertical velocity of an object would be just before it hits the ground?

8. Calculating final horizontal final velocity
Horizontal Velocity
Vertical Velocity
∆x = 9.2
∆y = m
Vi = 6 m/s
Vi = 0 m/s
a = 0 m/s
a = 9.8 m/s
t = 1.53 s
U: Vf
E: Vf = Vi + at
S: Vf = (6) + (0)(1.53)
S: Vf = 6 m/s

9. Calculating final vertical final velocity
Horizontal Velocity
Vertical Velocity
∆x = 9.2
∆y = m
Vi = 6 m/s
Vi = 0 m/s
a = 0 m/s
a = 9.8 m/s
t = 1.53 s
U: Vf
E: Vf = Vi + at
S: Vf = (0) + (9.8)(1.53)
S: Vf = m/s

10. Practice with your elbow partner