of the path of an object moving in a circle at constant speed is halved.

• Question 1 An object moving in a circle at constant speed is accelerated • Question 2 A bullet is fired upward. As it rises, • Question 3 The radius of the path of an object moving in a circle at constant speed is halved. If the speed remains the same, the centripetal force needed is • Question 4 If the moon were half as far from the earth as it is now, the gravitational force it exerts on the earth would be • Question 5 Relative to what she weighs on the earth, an astronaut visiting another planet • Question 6 A moose weighing 3 kN is standing still. The force the ground exerts on the moose is • Question 7 A snail travels 45 cm in 20 min. Its average speed is • Question 8 Which of the following units could be associated with a vector quantity? • Question 9 Of the following, a molecule is best described as • Question 10 The properties of several different materials are being compared. If the samples all have the same volume, the one with the greatest mass also has the greatest • Question 11 Which of the following is not true of molecular motion in a gas? • Question 12 The circulation of hot air in a room is an example of transfer of heat by • Question 13 When heat is added to a body of matter, the resulting temperature increase does not depend upon • Question 14 The pressure at the bottom of a barrel filled with liquid does not depend on the • Question 15 The temperature of a gas sample in a rigid container is reduced. The pressure the gas exerts on the container walls decreases because • Question 16 Ice floats in water because • Question 17 The concept that gravitation is a distortion of space-time is part of • Question 18 Which of the following quantities is always the same to all observers? • Question 19 The angular momentum of spinning object depends, in part, on its mass and how fast it is spinning.  Consider the following situation:  a skater spins slowly on one skate, with her arms and the other leg extended.  As she pulls in her arms and extended leg, she spins faster.  This is because • Question 20 The linear momentum of a 400-kg giraffe galloping at 5 m/s is • Question 21 An object that has linear momentum must also have • Question 22 The watt is a unit of • Question 23 What never changes when two or more objects collide is • Question 24 On a molecular level heat is • Question 25 The current with which a transformer is used • Question 26 Coulomb’s formula F = KQ1Q2/R2 gives the force between two charges in free space. The value of K • Question 27 Which of the following statements is not true? • Question 28 A negative electric charge • Question 29 An object has a positive electric charge whenever • Question 30 A drawing of the field lines of a magnetic field provides information on • Question 31 The relationship between voltage, current, and resistance in a metallic wire: • Question 32 When an observer moves past a stationary electric charge, she detects • Question 33 When first proposed, a scientific idea is usually called a • Question 34 The period of the earth’s orbit around the sun is • Question 35 If the earth had no moon, • Question 36 Stars and planets are round because • Question 37 The scientist who showed that gravity accounts for Kepler’s laws of planetary motion was • Question 38 What distinguishes the scientific method from other ways of looking at the natural world is • Question 39 Scientific theories • Question 40 In which one or more of the following is the earth assumed to be the center of the universe?