130 likes | 203 Views
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
E N D
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…
Announcements • Turn HW into the blue bin • Turn in signed progress reports into the blue bin • SELL SOME FRUIT • DO NOT WALK OUT OF CLASS WITHOUT TURNING YOUR NOTEBOOK IN
Notebook Quiz • What is the definition of POSITION? • What is the unit of FORCE? • What is the formula to calculate speed? • What do you plot along the Y-axis on a Distance-Time graph?
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 ball stops, there must be a force acting to slow the ball down. The force that slows the ball to a stop is FRICTION.
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. Sliding Friction Force Direction of Slide
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! • You use a lot of force to slide a desk across the floor. • You’re riding a skateboard down the street and it slowly rolls to a stop. • You try to push the couch, but can’t seem to move it. FLUID FRICTION SLIDING FRICTION ROLLING FRICTION STATIC FRICTION Friction Force
LAB PRACTICE! MU OF THE SHOE!!!
EXIT TICKET • What happens when you wear socks and walk on a wood or tile floor? Why do you think this happens? • What causes a baseball or football to slow down in the air? • How many forces are acting on you when you sleep? How many forces are acting on you when you sit in class?