1. The average velocity is greatest: a) between A and B b) between B and C c) between A and C Quizzes from Scott Pratt’s Lectures

A football is thrown with a velocity v 0 at an angle of 45 degrees above the horizontal. Which of the expressions for the distance of the throw, D, is correct?

a)A only b)A and B only c)A, B and C only d)All statements e)None of the statements 2) Which statements are correct? Assume the objects are static. A) T 1 must = T 2 B) T 2 must = T 3 C) T 1 must be < Mg D) T 1 +T 2 must be > Mg cos(10 o )=0.985 sin(10 o )=0.173

1. What is your section number? 2. A wheel of radius 7 m rotates at 300 rpm. What is the linear speed of a point on the rim? a)140  m/s b)35/  m/s c)70  m/s d)300/  m/s e)600  m/s

1.What is your section number? 2.What is T R, the tension in the right-side cable? Given: Mg = 2400 N a) 400 Nb) 600 N c) 800 Nd) 1200 N e) 3000 N

1.What is your section number? 2.In order of largest to smallest, list the objects according to their moment of inertia. All three objects have the same mass M which is uniformly distributed in the plane according to the green color. cylinder block 2a a block a a)Cylinder, big block, little block b)Little block, big block, cylinder c)Big block, little block, cylinder d)Big block, cylinder, little block e)None of the above

1. What is your section number? 2. How many calories are required to heat one liter of water from 20 ºC to 30 ºC? a)10, 000 b)20,000 c)23.45 d)50,000 e)320,000

1. What is your section number? 2. In an effort to reduce heating costs in his bunker, Dictator Dan doubles the thickness of his concrete walls. Which of the following is true? a) The conductivity gets doubled b) The conductivity is halved c) The R-value is doubled d) The R-value is halved e) None of the above

1. What is your section #? 2. A massive copper piston traps an ideal gas as shown to the right. The piston is allowed to freely slide up and down and equilibrate with the outside air. Pick the most correct statement? A. The pressure is higher inside the cylinder than outside. B. The temperature inside the cylinder is higher than outside the cylinder. C. If the gas is heated by applying a flame to cylinder, and the piston comes to a new equilibrium, the inside pressure will have increased. D. All of the above. E. A and C.

1. What is your section #? 2. A massive piston traps an amount of Helium gas as shown. The piston freely slides up and down. The system initially equilibrates at room temperature, T = T a = 20 ºC (a) The gas is then slowly heated until T = T b = 100 ºC (b) A. P a = P b B. W ab > 0 C. Q ab > W ab D. All of the above. E. A and C. Outside Air: Room T, Atm. P Vocabulary: W ab is work done by gas between a and b Q ab is heat added to gas between a and b

1. What is your section #? 2. You are designing an ideal Carnot engine which will exhaust heat near room temperature at T = 27 ºC. If you want the engine to be 75% efficient, what is the minimum temperature of the heat reservoir? A. 27 ºC B. 127 ºC C. 327 ºC D. 627 ºC E. 927 ºC DATA: 0 ºC = 273 ºK