Take out your morning article and begin working silently. When you finish, you may take a book from the bookshelf. Agenda: Homework and flash cards due Friday. 1. Explain the motion of [figure a] in the picture. Be sure to describe the reference directions. 2. What is the reference point in this example? 7.P.1.2 Explain the effects of balanced and unbalanced forces acting on an object (including friction, gravity and magnets) Vocabulary Words 1. unbalanced force 2. balanced force 3. mass 4. friction 5. gravity 6. inertia 7. velocity 8. newtons 9. magnets 10. force 11. frame of reference Balanced Force Balance forces are two forces acting in opposite directions on an object, and equal in size. Anytime there is a balanced force on an object, the object stays still or continues moving continues at the same speed and in the same direction. Unbalanced Force 1. When two forces acting on an object are not equal in size. 2. Unbalanced forces cause: a still object to move, an object to speed up or slow down, a moving object to stop, a moving object to change direction. Magnet An object that is surrounded by a magnetic field and that has the property, either natural or induced, of attracting iron or steel. newton (symbol: N) is the International System of Units (SI) derived unit of force. Notebook Title: Speed and Motion Testable Question: How can you measure speed? = Raise your hand to ask questions during the lab = stay positive and work as a team! Motion Definition: A change in position over time. The ball moved from position 6 to position 3. 1 2 3 4 5 6 7 8 9 Speed Definition: The rate of motion. (how fast motion happens) Speed is the measure of how fast something moves or the distance it moves, in a given time. Ball 1 moved 5 meters in 2 seconds. (Slower speed) Ball 2 moved 10 meters in 2 seconds. (Faster speed) Calculating Speed speed = distance ÷ time Units: meters/seconds (m/s) miles/hour (mph) kilometers/hour (km/h) 1. If something travels 50 miles in one hour, what is its speed? 50 miles 1 hour 2. If something travels 4 meters in one second, what is its speed? 4 meters 1 second 3. = 50 miles per hour = 4 meters per second = 4 m/s If something travels 10 miles in two hours, what is its speed? 10 miles 2 hours = 5 miles per hour Question CORNELL What is speed? Notes SYTLE Speed is the measure of How are speed and position related? (hint: the library is 2 blocks away or the library is 5 minutes away) how fast something moves or the distance it moves in a given amount of time. (RATE of MOTION) Speed and position both deal with where an object is. Question Notes Speed = distance divided What is the by time formula used to calculate speed? S=d/t Practice Calculating Speed 1. A man runs 200 m in 25 s. What is his speed? 2. If you travel 100 m in 50 s, What is your speed? 200 m / 25 s = 8 meters per second 100 m / 50 s = 2 meters per second 3. A women traveled 500 m in 20 s. What was her speed? 500 m / 20 s = 25 meters per second 4. A wheelchair racer completes a 100 meter course in 20 seconds. 100 m / 20 s = 5 meters per second Speed Triangles! Flip over your note sheet to see how they work! D S ÷ T x 1. Speed Distan = _______ Time _______ ce D S ÷ T x 2. Distance =Spe _______ Time _______ ed D S ÷ T x 3. Time =Distan _______ Spe _______ ce ed D S ÷ T x 4. Distance = 10 meters, Time = 1 sec. Speed = 10 m ÷ S 1s x 5. Distance = 50 meters, Time = 10 sec.5 m/s Speed = 50 meters D 10 seconds ÷ S T x 6. Distance = 80 miles, Time = 2 hours40 m/h Speed = D 80 miles ÷ 2 hours S T x 7. Distance = 80 miles, Speed = 40 miles/hour Time = 80 miles 40 miles/hour x ÷ T Sometimes, speed questions are word problems. Just set up your speed triangle! 1. Joe jogged for 1 hour. He ran 6 miles. What was his speed in miles/hour? 6 miles / 1 hour = 6 m/h 2. Alex jogged for 2 hours. He ran 4 miles. What was his speed in miles/hour? 4 miles / 2 hours= 2 m/h 3. Jose threw a ball. It traveled 50 meters in 5 seconds. What was its speed in meters/second? 50 meters/ 5 seconds= 10 m/s 4. Ms. Reynolds was going 60 miles/hour on the freeway. How far did she get after 1 hour? 60 miles x 1 hour = 60 miles 5. Ms. Wright was going 60 miles/hour on the freeway. How far did she get after 2 hours? 60 miles x 2 hours = 120 miles Can you calculate speed with speed? Use speed triangles to solve practice problems. The first person in each table to get all correct will win a prize! Work independently (silently). Raise your hand if you have a question. Be on task! Exit Ticket 1. Speed = ________ _________ 2. A train travels for 3 hours. It goes 90 miles. What was its speed? 3. A car is going 60 miles/hour. How far will it go in half an hour? 4. A boat is going 25 miles/hour. How long will it take for it to travel 100 miles? 5. 1 mile/minute = ___ miles/hour