What is science / physics? •A consistent picture of how the world works •Backed up by data •Predictive •Done by (relatively) normal people •Evolving •Useful for technology •Sometimes transformational for humanity Big ideas •Newton’s 3rd law •Work and conservation of energy, mechanical advantage •Friction and Entropy, 2nd law of thermodynamics •Mass and Weight •Heat •Phases of matter •Radiation and light •CMBR •Electromagnetic induction •Structure of atoms and nuclei •Resonance How things work •Bicycles •Air conditioners / refrigerators / dehumidifiers •Car engines •Light bulbs •Atomic clocks, GPS •Circuits, flashlights •AC power distribution •Generators, Motors •Radio, cell phones •Microwave ovens •Nuclear weapons and power •X-rays, CAT scans, MRI, radiation therapy Many of you went outside of your comfort zone… …good for you! A battleship simultaneously fires two shells toward two enemy ships, one close by (A), one far away (B). The shells leave the battleship at different angles and travel along the trajectories indicated below. Which of the two enemy ships gets hit first? (Muzzle speed is constant) Two light bulbs are connected in series to a battery. When a wire is connected across light bulb 1, light bulb 2 2 1 (A) glows more brightly (B) glows more dimly (C) does not change (D) goes out Two uniformly charged spheres are fastened to pucks on an air hockey table. The charge on sphere 2 is three times the charge on sphere 1. Which force diagram correctly shows the magnitude and direction of the electric forces: (A) (C) (B) (D) A box, with its center-of-mass off-center as indicated by the dot, is placed on an inclined plane. In which of the four orientations shown, if any, does the box tip over? A ladybug sits at the outer edge of a merry-go-round, and a gentleman bug sits halfway between her and the axis of rotation. The merry-go-round makes a complete revolution once each second. The gentleman bug’s angular speed is A. half the ladybug’s. B. the same as the ladybug’s. C. twice the ladybug’s. D. impossible to determine A 10-kg weight is suspended from the ceiling by a spring. The weight-spring system is at equilibrium with the bottom of the weight is about 1 m above the floor. The spring is then stretched until the weight is just above the eggs. When the spring is released, the weight is pulled up by the contracting spring and then falls back down under the influence of gravity. On the way down, it (A) smashes the eggs (B) reverses its direction far above the eggs (C) reverses direction exactly when it reaches the eggs A nitrogen nucleus has 15 nucleons. The atomic number of nitrogen is 7. The number of protons in this nucleus is (A) 7 (B) 8 (C) 15 (D) 22 A tank circuit is built from which components? (A) Battery and inductor (B) Inductor and capacitor (C) Capacitor and resistor (D) Resistor and battery An MRI device uses (A) Magnets and gamma rays (B) Magnets and beta rays (C) Magnets and alpha rays (D) Magnets and radio waves A CT scan uses (A) X rays (B) Microwaves (C) Delta rays (D) Lasers When an air conditioner cools a room, it (A) decreases the air pressure in the room. (B) decreases the entropy in the room. (C) decreases the entropy outside of the room. (D) violates the second law of thermodynamics. The musical scale where each successive note has a frequency bigger by a factor of the twelfth root of 2 (approximately 1.06) is called the (A) well-done scale. (B) well-tempered scale. (C) equal-tempered scale. (D) hot-tempered scale. I hope that you had fun in PHYS 140! Keep in touch!
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