Name: _______________________________ Mid-term Test Study Guide Period: _____________ Forces & Newton’s Laws Ch. 18 (pages 522-538) Ch. 19 (pages 550-568). 1. Define the following terms: Force- a push or a pull Balanced forces- forces that cancel each other out and do not change an object’s motion Unbalanced forces- forces that are not equal and cause the motion of an object Friction- a force that resists sliding between two touching surfaces; slows down an object’s motion Acceleration- a change in speed or direction Inertia- an object’s tendency to resist a change in motion Momentum- measure of how hard it is to stop an object 2. What is the formula for speed? Speed= distance/ time 3. What two factors must you know to calculate velocity? Speed and Direction 4. Forces act: a. alone b. in pairs 5. What does the Law of Conservation of Momentum state: the total momentum of objects that collide with each other does not change 6. Describe and give an example of Newton’s 1st law of motion. An object at rest will remain at rest and an object in motion will remain in motion until an unbalanced force acts on it. 7. Describe and give an example of Newton’s 2nd law of motion. Force= mass x acceleration 8. Describe and give an example of Newton’s 3rd law of motion. For every action there is an equal and opposite reaction Name: _______________________________ Period: _____________ Energy & Waves Ch. 21 (pages 608-623) Ch. 24 (pages 694-713) 9. What happens to the molecules of a substance when it is heated? Molecules speed up 10. How do particles move when a transverse wave moves through it? Particles move back and forth at right angles to the direction in which the wave travels. 11. Heat transfers from one object to another because of a change in what? temperature 12. Draw a transverse wave and LABEL the crest and trough. 13. Draw a compressional wave and LABEL the compression and rarefaction. 14. What type of waves are sound waves? Compressional waves 15. Define the following key terms: Pitch- human perception of the frequency of sound Wave- disturbance that moves through matter or space Diffraction- bending of waves around an object Refraction- change in direction of a wave when it changes speed as it travels Wavelength- distance between one point on a wave and the nearest point moving with the same speed and direction Name: _______________________________ Period: _____________ Plates & Volcanoes Ch. 7 (pages 182-199) Ch. 8 (pages 210-231) 14. What evidence supports seafloor spreading? The youngest rocks are located at mid-ocean ridges. 15. List the 3 different types of plate boundaries and describe how they move. Convergent- collide Divergent- divide Transverse- slide past one another 16. List 4 different features caused by plate tectonics. Faults, rift valleys, mountains, volcanoes, earthquakes 17. Define the following key term: Hot spots- large rising bodies of magma not at plate boundaries Epicenter- point on Earth’s surface above where the earthquake occurs Focus- underground center of an earthquake Fault- break in Earth’s rocks caused by stress Shield- volcano formed by gentle eruptions Name: _______________________________ Period: _____________ Fossils & Geologic Time Ch. 9 (pages 242-261) Ch. 10 (pages 272-293) 18. Define the following key terms: Principle of Superposition- process of reading undisturbed rock layers. States that older rocks on are the bottom while younger rocks on are top. Half-life- time it takes for half the atoms in an isotope to decay. Absolute age- age in years of a rock or other object; determined by properties of atoms. Relative age- how old something is in comparison with something else 19. List some important events for each of the following time periods: Precambrian time- Little is known because most Precambrian organisms lacked hard parts. Rocks from this time were deeply buried and changed by heat and pressure. Mesozoic Era- Pangaea separated, Dinosaurs evolved, Gymnosperms and Angiosperms appeared, a great extinction caused by a comet or an asteroid occurred. Paleozoic Era- Amphibians evolved to survive in water and on land, Reptiles evolved from amphibians, a great extinction occurred at the end of the era Cenozoic Era- Many mountain ranges formed, humans appeared 20. Organisms with hard parts are more likely to become fossils than organisms that don’t have these. 21. A fossil that forms when sediments fill a mold and hard into rock is known as a: cast 22. A cavity in rock left when the hard parts of an organism decay is known as a: mold 23. Remains, imprints, or traces of prehistoric organisms are known as: fossils 24. Define and give an example of an index fossil. The remains of a species that lived for a short time, were numerous and were found in many places. Ex: trilobites 25. Metamorphic rock is formed by heat and pressure. 26. Sediments are formed by weathering and erosion. 27. Magma is formed by melting. 28. Igneous rock is formed when magma cools. 29. Sedimentary rock is formed by cementation and compaction.