Warm up• A swimmer is resting at the edge of the pool talking to his coach. The coach

then begins walking along the edge of the pool. The swimmer swims to the opposite edge to beat the coach. If the swimmer is walking with an average velocity of 2.5 m/s, how fast does the swimmer have to beat the coach to the opposite side? Dimensions of the pool 50 m by 25m.

Lab from Friday

• Use constant velocity to solve all problems• Average Walking velocity = 1m/s• Average Sprinting velocity = 5 m/s

• Classes that didn’t complete all sections , get data from other groups just reference them

Physics HonorsA/B–Day

10/06 – 10/07/152D motion

Agenda• 2 dimensional motion – Relative motion• Projectile motion• Examples

• Work on problems

Recall Vectors• Vectors have components

𝑉

𝑉 𝑥

𝑉 𝑦

• Vector components affect the resultant vector but not the other vector

• Let’s reduce the vector by

Recall Vectors• Vectors have components

𝑉

𝑉 𝑥

𝑉 𝑦

• Vector components affect the resultant vector but not the other vector

• Let’s reduce the vector by

• Observe how is unchanged

Example problem• A plane flies north at a velocity of 100 km/hr against a headwind of

25 km/hr. What is the resultant velocity?

Example problem• A plane flies north at a velocity of 100 km/hr with a tailwind of 25

km/hr. What is the resultant velocity?

Example problem• A plane flies north at a velocity of 100 km/hr with a sidewind of 25

km/hr east. What is the resultant velocity?

So how do we perceive relative motion• Relative motion

Which coordinate am I in?• If given resultant and then we are in Polar Form

• If given the components, then vector can be written in component form or unit vector notation.

Projectile Motion• What is a projectile?

What is a projectile and projectile motion?

• A projectile is any object that is only being accelerated by gravity.

• The objects we have been throwing up until now have been projectiles as well.

Ex. Throwing balls at an angle above the horizontal.

Ex. Throwing ball horizontally off a cliff.

Projectile Motion

Projectile Motion

Projectile Motion

Projectile MotionAt the maximum height

Projectile Motion

Projectile Motion

Projectile Motion

Projectile Motion• Ball has initial velocity

in the x and y directions

Projectile Motion• As ball goes into

motion, stays the same and gets smaller up until it reaches it maximum height

Projectile Motion• stays the same

• gets smaller up

Projectile MotionAt the maximum height

• is present with the same magnitude and direction

• = 0

Projectile Motion• As ball goes into down,

stays the same and gets larger down

Projectile Motion• stays the same

• gets larger down

Projectile Motion• Ball has returns to

ground with same magnitude as initial velocity in the x and y directions

• However has changed directions

How can we look at these motions

Horizontal Motion (x) Vertical Motion (y)

Velocity Constant Changing Acceleration No acceleration; a = 0 Constant a

So that means what about the equations we use in each direction

𝑣𝑎𝑣𝑔=∆ 𝑥∆ 𝑡

X – direction (Horizontal) y – direction (Veritcal)

Example Problem• A baseball is thrown at an angle of 25 at a velocity of 23.0 m/s. The ball was

caught at the same level it was thrown by a second player. • How long was it in the air? What was the highest point in the ball’s path? How

far away are the two players from each other?

Example Problem• Two kids are sliding a plate back and forth to each other. One misses

and it slides off the table. If the table is 1.05 m high and the plate flies off the table with a horizontal velocity of 0.74 m/s. How long does it take to fall to the ground? How far from the end of the table does it land?