300 likes | 506 Views
Ch 3 Notes. Mr. Russo Beaumont High School. Objective Ch 3.1-3.3 (Pg32). We will be able to find the MAGNITUDE of the RESULTANT when given two or more vectors. Vector Quantity. Vector Quantity - A quantity that requires both MAGNITUDE and DIRECTION Speed vs. Velocity 70mph or
E N D
Ch 3 Notes Mr. Russo Beaumont High School
Objective Ch 3.1-3.3 (Pg32) • We will be able to find the MAGNITUDE of the RESULTANT when given two or more vectors
Vector Quantity • Vector Quantity - A quantity that requires both MAGNITUDE and DIRECTION • Speed vs. Velocity • 70mph or • 70 mph North
Scalar Quantity • Scalar Quantity – A quantity that is described by MAGNITUDE ONLY • 3 kg of sand • 5 Liters of water • 75 minutes
Important Point • MAGNITUDE IS JUST A NUMBER! • Example – What is the magnitude of your age?
Vector • Vector – An arrow that is used to represent the MAGNITUDE and DIRECTION • Length of arrow = Magnitude (Ex: Speed of car) • Where it is pointing = Direction (Ex: Where car is going)
What is the velocity of the plane with the wind? • 80 km/hr (plane) • 20 km/hr (wind) • Total = 100 km/hr
What is the velocity of the plane against the wind? • 80 km/hr (plane) • -20 km/hr (wind) • Total = 60 km/hr
Resultant Vector • Resultant Vector – The sum of two or more vectors
What formula do you use if two vectors are perpendicular? • Pythagorean Theorem (a2 + b2 = c2) 60km/hr Head to Tail Method (Book teaches parallelogram method) 80km/hr 100km/hr 60km/hr
Components • Components – Any vector can be changed into 2 “pieces” that are perpendicular to each other Figure 3.6
Is it possible to surf a wave and go faster than the wave? • Yes Riding wave at a larger angle Going with wave Riding wave at an angle
Objective: Notes 3.4-3.5 (Pg 35) • We will be able to explain how the path of the projectile can be broken down into its x and y components.
Projectiles • Projectile – Any object that moves through space and is only acted on by gravity
Describe the horizontal component of a projectile? • Just like a ball rolling across a table • Constant velocity (Equal spacing in equal intervals of time) • No Acceleration • No Horizontal Force
Describe the vertical component of a projectile? • Just like free fall • There is a force due to gravity • The projectile will accelerate downward
How are the vertical and horizontal components related? • They are independent of each other. • A projectile moving up and down does not affect how it moves left or right
What does this mean? • Explain Rifle Scenario • Explain Monkey and Hunter Scenario • Show Monkey and Hunter videos
What do you notice about the Horizontal component? • The vertical component is the same because… • There is no force acting horizontally
What do you notice about the vertical Component? • Vertical component looks just like an object in free fall • Gravity is the only force vertically
What angle will give a projectile the most distance? • 45 degrees
What is the relationship between 60° and 30°? • If kicked with the same force, they land in the same spot
When is the path not a true parabola? • When we take into account air resistance.
What is the speed of a projectile when it hits the ground? • The same speed as when it started.
Projectile Motion Example Problems • Harry accidentally falls out of a helicopter that is traveling 15 m/s. He plunges into a swimming pool 2 seconds later. Assuming no air resistance, what was the horizontal distance between Harry and the swimming pool when he fell from the helicopter?
Projectile Motion Example Problems • While standing on a 10.0-m-high quarry wall, Clarence tosses a piece of granite into the water below. If Clarence throws the rock horizontally with a velocity of 3.0 m/s, how far out from the edge of the cliff will it hit the water?
Projectile Motion Example Problems • Joe stands on a jetty hitting golf balls into the river below. If Joe hits a golf ball with a horizontal velocity of 45 m/s, and it lands in the water a horizontal distance of 200 m from where Joe is standing, what is the height of the jetty?
Projectile Motion Example Problems • Harry and Angela look from their balcony to a swimming pool below that is 15m from the bottom of their building. They estimate the balcony is 45 meters high. How fast would they have to jump horizontally to reach the pool?
Projectile Motion Example Problems • A boy on a 20 m high tower throws a ball a distance of 60m. What speed is the ball thrown?