Foundation Science FINAL TEST REVIEW
- 1. Review for Final Vocabulary….. • Gene transfer – moving of a gene from one organism to another • Transgenic animal – animal that has had foreign DNA put into its cells • Cerebrum – part of the brain where thinking takes place • Biotechnology – technology used in agriculture, food science, and medicine • Impulses – a message carried by a neuron • Neurons – the basic functioning units of the nervous system • Cloning – copying a plant or animal • Microinjection – injecting DNA into a cell using a small needle and microscope • Carcinogens – promote the growth of cancer cells • Synapse – the space between neurons • Depressant – drug that slows down the processes of the nervous system • Stimulant – drug that speeds up the activities of the nervous system
- 2. More Vocabulary…. The central nervous system is made up of the brain and spinal cord Artificial insemination is when a male’s sperm (semen) is inserted into a female A force is a push or pull with direction
- 3. Displacement vs Distance Distance – how far something moved (meters) Displacement – how far, AND what direction something moved (meters to the NW) Is the red or yellow line distance? DISTANCE Red is distance = how far moved Finish Yellow is displacement = how far and what direction DISPLACEMENT Displacement is always a straight line, and will always be shorter than distance Start
- 4. What is a Force? A force is a push or pull on an object with direction A force has a size AND a direction Is a force a scalar or vector quantity? Examples of forces: -Pushing your book across a table -Pushing a box A force must have a direction, so it is a vector quantity
- 5. The Units of Force Force is measured in Newtons Newton is abbreviated “N” Newton (N) = kg x m/s2 m/s2 is acceleration So, one Newton is the amount of force that will accelerate a 1 kg object at 1m/s2 Force is mass x acceleration f ma
- 6. Forces are shown as arrows, or vectors The longer the arrow (vector), the greater the force The direction of the arrow shows you the direction of the force 10 N east N 5 N east Vectors
- 7. Adding Forces More than one force on an object will be added. So, if two people are pushing something east, one pushing with 5N, the other with 10N, what will be the net force on the box? 10 N east + 5 N east 15 N east = net force
- 8. Balanced and Unbalances Forces Balanced forces: when 2 forces cancel each other (no movement) 10 N force east 10 N force west f 10 N 10 N 0N There is no movement in balanced forces Example of a balanced force??
- 9. Balanced and Unbalances Forces Unbalanced forces: forces that do not cancel (create movement) 10 N force east 15 N force west 5 N west f 15 N 10 N 5 Nwest Unbalanced forces always create movement Example of an unbalanced force??
- 10. Draw a Balanced and Unbalanced force in Your Notebooks Unbalanced forces (create movement) 10 N force east 15 N force west 5 N west Movement to the west Balanced forces (do NOT create movement)
- 11. Newton’s First Law (law of inertia) What is Newton’s 1st law?? • Objects in motion stay in motion unless a force is applied to them • Objects at rest stay at rest unless a force is applied to them What is inertia?? • Tendency of an object to resist change in its state of motion Examples of inertia: -A person flies forward when a car stops -A person flying over bike handlebars
- 12. Newton’s Second Law Force is equal to an object’s mass times its acceleration f ma N = kg x m/s2 N/kg = m/s2 m/s2 = acceleration
- 13. Newton’s Third Law All forces exist in pairs For every action, there is an equal and opposite reaction THERE CANNOT BE ONE FORCE
- 14. Complete Questions in Notebook 1. Using the equation to the right, what will be more difficult to accelerate, an object with a f ma large or a small mass? 2. Explain Newton’s first, second and third laws and draw a picture to help explain each law.
- 15. ANSWERS 1. Using the equation to the right, what will be more difficult to accelerate, an object with a large or a small mass? f ma a = f/m so it will be easy to accelerate (move) objects with small mass, and hard to accelerate objects with a large mass. 1. Explain Newton’s first, second and third laws and draw a picture to help explain each law. Newton’s first law says that moving objects will keep moving, and that stationary (=not moving) objects will not move. It is sometimes called the law of inertia. Inertia is the tendency of objects to maintain their current state of motion. A man not wearing a seatbelt and flying out of a car is an example of inertia. Newton’s second law states that the force on an object is equal to its mass times its acceleration (f=ma). Newton’s third law says that for every action, there is an equal and opposite reaction. From this, we can deduce that forces must exist in pairs, and that there can never be a single force.
- 16. Review for Final 1. The displacement of a man walking on a curved road is (greater than, less than or equal to) his distance traveled? Less than 2. When you walk across the room the force on your feet is (greater than, less than or equal to) the force on the floor? Equal to
- 17. Mass vs Weight Mass is NOT the same as weight!! Mass – measure of how much matter an object contains Weight – an object’s mass (Kg) times its acceleration (m/s2) Mass does not change with location Weight does change with location Weight is a force and it is a vector quantity Mass is a scalar quantity with no direction Weight is measured in Newtons Mass is measured in Kg
- 18. This online weight calculator told me how much I weigh on different planets
- 19. Does Bart Weigh More on Earth or Jupiter? Bart weighs more on Jupiter because it’s a larger planet and has a stronger gravitational pull
- 20. Is Bart’s Mass Greater on Earth or Jupiter? 50 Kg 50 Kg Bart’s mass is the same everywhere in the universe. Mass never changes.
- 21. What is the difference between mass and weight? Write answer in your notebooks… Weight is measured in Newtons and is the product of mass times acceleration. Mass is how much matter an object contains and is measured in kg. The mass of an object will be the same anywhere in the universe, while the weight of an object will change depending on its location. Mass is a scalar quantity, while weight is a vector quantity which means it has direction.
- 22. How to calculate acceleration… A dog speeds up from 0 m/s to 21 m/s in 3 seconds. Calculate the dog’s acceleration in your notebooks 21 m/s – 0 m/s = 21 m/s per 3 seconds 21 m/s/3s = 7 m/s/s or 7 m/s2 Is acceleration a vector or scalar quantity? VECTOR!! Why is it m/s2 and not m/s/s? They are the same thing… m/s/s = m/s * 1/s = m/s2 m/s/s = m/s2