physical science ch 1
10) When you push your desk to the right, friction on the desk acts toward A) the left. B) at right angles to your push. C) the right. D) none of the above
A
13) When you stand at rest on a pair of bathroom scales, the readings on the scales will always A) each be half your weight. B) each equal your weight. C) add up to more than your weight. D) add to equal your weight.
A
17) When a crate slides down an incline at a constant velocity it is A) in dynamic equilibrium. B) in a state of being in and out of dynamic equilibrium. C) not in dynamic equilibrium. D) none of the above
A
6) A 50- N object falling in air experiences 30 N of air resistance. The amount of net force on the falling object is A) 20 N. B) 0 N. C) 80 N. D) 50 N.
A
7) Whenever the net force on an object is zero, its acceleration A) is zero. B) may be zero. C) and velocity are the same. D) none of the above
A
8) When a 10- N object is suspended at rest by two vertical strands of rope, the tension in each rope is A) 10 N. B) less than 5 N. C) 5 N. D) more than 5 N.
A
20) As an object freely falls, its A) acceleration increases. B) both C) velocity increases. D) none of the above
B
5) An object is pulled with three forces: one at 20 N to the right, another at 40 N to the right, and the third at 30 N to the left. The net force is A) 60 N to the left. B) 30 N to the left. C) 60 N to the right. D) none of the above
B
9) You hang from a pair of gym rings and the upward support forces of the rings will always A) add up to more than your weight. B) add up to equal your weight. C) each be equal to your weight. D) each be half your weight.
B
In contrast to Aristotleʹ s way of explaining nature, Galileo relied on A) mathematics. B) experiment. C) logic. D) patterns.
B
12) Place a book that weighs 10 N on a horizontal surface and the support force on the book is A) less than 10 N. B) greater than 10 N. C) 10 N. D) dependent on whether the book lies flat or stands upright.
C
14) An object in mechanical equilibrium is an object A) moving at constant velocity. B) with no acceleration. C) at rest. D) all of the above
C
15) A bucket of cement is raised by a rope at constant speed at a construction site. The upward force on the bucket supplied by the rope is A) less than the force of gravity. B) greater than the force of gravity. C) equal to the force of gravity.
C
16) The equilibrium rule ΣF = 0 applies to A) objects or systems in uniform motion in a straight line. B) objects or systems at rest. C) both D) neither
C
18) Youʹ re lying on the sand on a breezy day when a pesky fly wishes to join you. The breeze is blowing at a steady 2 m/s. In order for the fly to land on you it should hover over you while flying A) about 4 m/s relative to the breeze. B) faster than 2 m/s. C) with the breeze at 2 m/s. D) against the breeze at 2 m/s.
C
2) According to Galileo, inertia is a A) force like any other force. B) concept opposite to force. C) property of all matter. D) special kind of force.
C
11) Burl and Paul have a total weight of 1300 N. The tensions in the ropes that support the scaffold they stand on add to 1700 N. The weight of the scaffold itself must be A) 600 N. B) 500 N. C) 800 N. D) 400 N.
D
19) A motor scooter undergoes acceleration when it A) changes direction. B) gains speed. C) decreases speed. D) all of the above.
D
3) Compared with a 1- kg block of solid iron, a 2- kg block of solid iron has twice as much A) inertia. B) volume. C) mass. D) all of the above E) none of the above
D
4) Your weight is A) the same in all locations. B) a property of mechanical equilibrium. C) another word for your mass. D) the gravitational attraction between you and Earth.
D