WARM UP Please grab your sheet from yesterday

WARM UP: • Please grab your sheet from yesterday. – Finish the WEIGHT calculations from the FRONT by multiplying your mass in NEWTONS by the GRAVITATIONAL FORCE on each planet – Complete the backside of the sheet by diving the weight on each planet by Nicki Minaj’s mass (50 kg). CALCULATED FROM THE INFO ON PLANET EARTH…

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Notebook Quiz 1. What is the definition of POSITION? 2. What is the unit of FORCE? 3. What is the formula to calculate speed? 4. What do you plot along the Y-axis on a Distance-Time graph?

FRICTION

FRICTION • What will happen when the ball is released? • When the ball reaches the bottom of the slope, will it keep moving forever? Since The force the ball that stops, slowsthere the ball must tobe a stop a force is acting to. FRICTION. slow the ball down.

What is Friction? • Friction is a force that two surfaces exert on each other when they rub against each other. • The direction of the friction force is always OPPOSITE to the direction of the motion. Direction of Motion Friction Force

Types of Friction • Fluid friction occurs when a solid object moves through a liquid or gas. • Air resistance is a type of fluid friction. Direction of Motion Friction Force

Types of Friction • Sliding friction occurs when two solids slide over each other. • Sliding friction makes car brakes work and stops athletes from slipping. Direction of Slide Sliding Friction Force

Types of Friction • Rolling friction occurs when an object rolls across a surface. • Rolling friction is easier to overcome than sliding friction for the same materials. Direction of Motion Friction Force

Types of Friction • Static Friction opposes the motion of an object that is at rest • To make the object move, you have to exert a force larger than the force of static friction. Direction of Intended Movement Static Friction Force

Which type of friction is slowing down the object in each situation? • You are slipping down a waterslide at Treasure Island in Orlando! FLUID FRICTION • You use a lot of force to slide a desk across the floor. SLIDING FRICTION • You’re riding a skateboard down the street and it slowly rolls to a stop. ROLLING FRICTION • You try to push the couch, but can’t seem to move it. Friction Force STATIC FRICTION

LAB PRACTICE! MU OF THE SHOE!!!

EXIT TICKET 1. What happens when you wear socks and walk on a wood or tile floor? Why do you think this happens? 2. What causes a baseball or football to slow down in the air? 3. How many forces are acting on you when you sleep? How many forces are acting on you when you sit in class?