I.Matching (1) A. Force F. Newton K. Normal B. Balance Scale G. Spring Scale L. Mass C. Gravity H. Electromagnetic M. Field Forces D. Strong I. Equilibrium E. Inertia J. Friction
___1. Wrote the laws that we use to describe motion, Force, and gravity. ___2. When forces are balanced (net force=0).
II. Metric Conversions (2) 75mL = ___________________L
50mN = ___________________kN
61g = ___________________mg 220kL = ___________________L
0.25cm = __________________mm 348mL = ___________________cm3
6.5ms = ___________________s 3kg = ___________________g
1km = ___________________m 21km = ___________________cm
III. Why? Put a 1, 2, or 3 in each blank to tell us which of Newton's Laws this statement typifies. (2) ___If you apply a force to an object, it will accelerate. ___If you stop pedaling, you keep moving forward anyway. ___If you kick a bowling ball, it doesn't budge. ___If you kick a bowling ball, it hurts your foot. ___If you push a bowling ball just right, it goes. ___You push backward on the floor to walk forward.
IV. Problems – Vector Diagrams will be helpful for most. (5) ____________1. How much would a 60kg boulder weigh on the Moon where g= -1.7m/s2? (All other problems are assumed to be occurring on Earth.)
____________2. What is the weight of a 300g rock?
____________3. What is the mass of an 89N radio?
____________4. If a surface has a coefficient of friction of 0.87, and there is an object pressed against the surface with a force of 90N, what is the force of friction?
____________5. If there is a 60kg plow that must be pushed to the barn over an ice field with a coefficient of sliding friction of 0.15, how much force must the person use in order to accelerate the object at 1.8m/s2 if the plow is already slightly moving to start with?
____________6. If a helicopter with mass 3850kg is climbing at a rate of 5m/s2, find the force being exerted by the rotor atop the helicopter. (Think: would the rotor need to apply a force to make the helicopter hover?)
____________7. When a board sitting on the floor is raised to a 25o angle above the floor a moving hammer slides down the board with constant velocity. If the hammer has a mass of 1.2kg, what is the coefficient of sliding friction between the hammer and the board?
8. (Show all work) If a pulley system with two masses attached, one being 20kg and the other being 75kg, is released, what will happen to the objects? _______________________________________ ________________________________________________________________________________ ________________________________________________________________________________
V. Compare and contrast mass and weight. (10)
What is the difference between Mass and Weight? Essay? Short answer? How do you think we should handle this one?