Studied by 2 people
\n A car going around a curve at a speed of 20 miles per hour requires a centripetal force F in \n order to negotiate the turn. If the speed of the car were doubled, the required force would be
D) 4F
If only the direction of the net force on an object is known, which of the following can be \n determined?
B) The direction of the object's acceleration
A child is riding on a merry-go-round. If the rotational speed of the merry-go-round is \n doubled, the magnitude of the centripetal force acting on the child
D) is quadrupled
Orbiting astronauts on the space shuttle do not have weight in space because _____.
E) ... nonsense! The astronauts do have weight in space
A satellite is orbiting the Earth at a constant speed and a constant altitude above the Earth. The \n best words that could be used to describe the motion of the Earth-orbiting satellite is to say that \n the satellite is _____
A) in a state of free fall
A satellite is orbiting the Earth. If the mass of the Earth were somehow increased by a factor of \n 3 (without altering the orbital radius of the satellite), then the orbital speed of the satellite \n would ____ by a factor of ____.
A) increase, square root of 3
Four objects are attached to a 1-meter long string at various locations. The \n string is held at one end and twirled in a circle. The object that moves with the \n greatest linear speed is object ___
D) D
An object is moving in a circle at a constant speed of 30 m/s. It is known for sure that the \n object is accelerating because it is ____.
D) changing the direction of its velocity
An object moves in a circle at a constant speed. The direction of the acceleration vector is best \n described as being ____.
A) inward, towards the center of the circle
An eraser is tied to a string and held by a physics teacher. The eraser is whirled in a circle at \n constant speed. A 'God's eye' view of the circle is shown in the diagrams below.
\n If the teacher lets go of the string when the eraser is at the indicated position, then which one of \n the paths best represents the motion of the eraser?
Diagram A
A car makes a left-hand turn. The front-seat passenger claims that she feels a sensation of \n being pulled outwards. This is best explained by the fact that ____.
D) the passenger has a natural tendency to move tangent to and out of the circular path
Suppose you go with your friend on a roller coaster ride. After the ride, your friend describes \n the 'awesome outward pull on the second loop.' Such a statement only proves that your friend \n ____.
E) might not understand the physics of circular motion
Suppose that you are a passenger in a car. The car travels over the top of a small hill in the \n road at a high speed. As the car reaches the crest of the hill, you feel your body still moving \n upward; your glutis might even be lifted off the car seat. It might even feel like there is an \n upward push on your body. This upward sensation is best explained by the ____.
A) tendency of your body to follow its original upward path.
A car is making a turn on a level roadway. The type of force that causes the car to make the \n turn is the ____.
C) force of friction
An eraser is tied to a string and whirled in a horizontal circle at a constant speed. The type of \n force that causes the eraser to turn in a circle is the ____.
C) tension force
Suppose that you're at an amusement park and you get on a barrel ride. You stand on a \n platform with your back to the barrel wall. The barrel spins rapidly in a circle, the platform is \n suddenly dropped out from under you, and you continue moving in a circle. The type of force \n that causes you to turn in a circle is the ____.
a) normal force
A bucket of water is held by a rope and twirled in a vertical circle. \n The tension force acting upon the bucket would decrease to zero if
b) ) the acceleration decreased to a value of 9.8 m/s/s
Suppose that an object weighs 20 Newton on the surface of the earth (a distance of R from its \n center). If the same object is located a distance of R above the Earth's surface (a distance of 2R \n from its center), then the force of gravity upon it would be ____ Newton
a) 5.00
An astronaut is on the orbiting Space Shuttle, approximately 60 miles (~100 000 meters) above \n the surface of the Earth. (The Earth's radius is ~6 360 000 meters and its mass is ~5.98 x 1024 \n kg.) At this location, one might predict the acceleration of gravity to be ____.
c) a small percent less (1-10%) than 9.8 m/s/s
_____An object is moving at a constant speed of 20 m/s in a circle with a radius of 10 m. What \n is the time period of rotation of this object?
a) 1π seconds
_____Which equation(s) can be used to describe the motion of an object moving in a horizontal \n circle with a radius R, time period T and constant speed v?
A) Fc = mac B) vt = 2πR/T C) ac = vt2/R D) B and C E) A, B, and C
e) ) A, B, and C
_____ If the speed of an object moving around a circle is halved, without changing the radius, \n the acceleration of the object will
a) decrease by a factopr of four
_____An automobile traveling at a constant speed rounds a curve with a constant radius. The \n acceleration of the car is
c) directed toward the center of the circle
_____A horizontal turntable shown above rotates at a constant rate. \n As viewed from above, a coin on the turntable moves counterclockwise in a circle as shown. Which of the following \n vectors best represents the direction of the frictional force exerted on \n the coin by the turntable when the coin is in the position shown?
D) down arrow (see image)
_____Pictured is a downward view of a door with hinges on the left hand side. Which force \n produces the largest torque?
C) up arrow on right (see image)
_Which statement best describes motion in the solar system?
b) ) The Earth makes one revolution around the sun each year.
_An object moving with constant speed in a circular path has a net force acting on it \n directed:
a) inward toward the center of the circle
_____Which diagram has a torque about O equal in magnitude to the torque \n about X in the diagram to the right?
C) see images
_In a carnival ride, people of mass m are whirled \n in a horizontal circle by a floorless cylindrical room of \n radius r, as show in the diagram. If the coefficient of \n friction between the people and the tube surface is μ, \n what minimum speed is necessary to keep the people \n from sliding down the walls?
B) )√(rg/μ)
A square piece of plywood on a horizontal tabletop is subjected to the two \n horizontal forces shown above. Where should a third force of magnitude 5 \n newtons be applied to put the piece of plywood into equilibrium?
a) down arrow on top right (see image)
A system of two wheels fixed to each other is free to rotate \n about a frictionless axis through the common center of the \n wheels and perpendicular to the page. Four forces are exerted \n tangentially to the rims of the wheels, as shown above. The \n magnitude of the net torque on the system about the axis is
b) 2FR
A uniform stick has length L. The moment of inertia about the center of the stick is Io. A \n particle of mass M is attached to one end of the stick. The moment of inertia of the \n combined system about the center of the stick is
a) see image
An ice skater is spinning about a vertical axis with arms fully extended. If the arms are \n pulled in closer to the body, in which of the following ways are the angular momentum and \n kinetic energy of the skater affected?
c) Angular momentum remains constant and kinetic energy increases
A fast-moving train blows its horn as it travels at a constant speed toward an observer \n standing just off the train tracks. The horn's frequency is 250 Hz. Of the following \n statements about the sound heard by the observer, which is correct?
c) The observer hears a constant frequency sound of greater than 250 Hz
A sound wave travels with a speed of 340 m/s and has a wavelength of 2.0 m. What is the \n wave's frequency?
b) 170 Hz
Which circuit diagram correctly shows the connection of ammeter A and voltmeter V to \n measure the current through and potential difference across resistor R?
d
A boy plays a note on a piano. The wavelength of the resulting wave is 2.0 m and its speed \n is 340 m/s. He now plays a second note with twice the frequency of the first. Of the \n following statements about the wavelength and speed of the second note, which is correct?
a) The second note has a wavelength of 1.0 m and a speed of 340 m/s.
The diagram shows a transverse wave moving to \n the right. What is the size of the distance \n marked "X" in the diagram?
b) ) the amplitude
Two identical resistors are connected in parallel. The equivalent resistance for this \n arrangement is 24Ω. What is the resistance of each resistor?
d) 48 Ohms
A 20 Ω resistor and a 40 Ω resistor are connected in series to a battery. Of the following \n statements about the resistors, which is correct?
d) ) The current in the 40 Ω resistor is equal to the current in the 20 Ω resistor
Which bulb in the chart dissipates the most \n power?
b) Bulb B
Which bulb in the chart has the greatest \n operating resistance? \n
d) Bulb D
A sound of constant frequency is produced by the siren on top of a firehouse. Compared to \n the frequency produced by the siren, the frequency observed by a firefighter approaching \n the firehouse is
b) higher
Two sound waves are produced by a musical instrument. One wave has a frequency of 200 \n Hz and the other has a frequency of 400 Hz. Of the following statements about the \n wavelengths of the two waves produced, which is correct?
c) The wavelength of the 400 Hz wave is one half the wavelength of the 200 Hz wave.
Identical resistors (R) are connected across the same 12 V battery. Which circuit uses the \n greatest power?
d) see image
Which is the wavelength of the wave shown?
d) 5.0 m
What is the amplitude of the wave shown?
a) 1.0 m
When an electric heater is connected to a 12 volt battery the heater dissipates 72 watts of \n power. What is the current in the heater?
b) 6.0 A
A child rubs a rubber balloon on her sweater causing the balloon to become negatively \n charges. Of the following statements about the balloon, which is correct?
A) The balloon has more electrons than protons. \n B) The balloon has more protons than electrons. \n C) The balloon has equal protons and electrons. \n D) The balloon and sweater have equal electrons.
a) The balloon has more elctrons than protons
A 2.0Ω resistor and a 4 Ω resistor are connected in series to a 12 V battery. Of the following \n statements about the resistors, which is correct?
A) The current in the 2 resistors is equal. \n B) The current in the 2 Ω resistor is half as great as the current in the 4 Ω resistor. \n C) The current in the 2 Ω resistor is twice as great as the current in the 4 Ω resistor. \n D) The current in the 2 Ω resistor is four times as great as the current in the 4 Ω resistor.
A) The current in the 2 resistors is equal.
Given the illustrated simple electrical circuit. If the current in all 3 \n resistors is equal, which of the following statements must be true?
C) X and Y added together have the same resistance as Z
When the rate of electron flow passing through a resistor is doubled, the voltage drop across \n the resistor is
A) doubled
What is the current in the 6 Ohm resistor shown in the \n diagram?
C) 1.5 A
Solid material which are good conductors of electricity have many loosely bound
C) electrons
Assume that waves are propagating in a uniform medium. If the frequency of the wave \n source doubles then
D) ) the wavelength of the waves halves
A small vibrating object S moves across the surface \n of a ripple tank producing the wave fronts shown. \n The wave fronts move with speed v. The object is \n traveling in what direction and with what speed \n relative to the speed of the wave fronts produced?
B) see image
Two different wattage light bulbs connected in series with a battery will have the same
A) current
A metal wire connected to a 12 V battery has a current of 0.30 A flowing through it. What is \n the resistance of the wire?
D) 40 Ohms
An electric toaster has a resistance of 6 Ohms when it is operating at 120 V. What is the \n current in the toaster?
C) 20 A
A 2.0 Ohm resistor and a 3.0 Ohm resistor are connected in parallel. What is their equivalent \n resistance?
A) 1.2 Ohms
A 4 Ohm and an 8 Ohm resistor are connected in series to a voltage source. The current \n through the 4 Ohm resistor is 2.0 A. What is the current through the 8 Ohm resistor?
B) 2 A
Two pulses, A and B, approach each other along a rope as shown in the diagram. Which of \n the following \n diagrams indicates \n the resulting wave \n form when the peak \n amplitudes on both \n pulses are at point X?
B) See Image
When a glass rod is rubbed with silk the glass rod becomes positively charged. Of the \n following statements, which correctly explains this phenomenon?
C) ) Electrons are transferred from the glass to the silk
Of the following combinations of current and voltage, which uses the greatest amount of \n power?
B) 4A @ 12 V
Of the following diagrams, \n the one that best shows the \n Ohm's Law relationship \n between voltage and current \n for a constant resistance is
D) See image
A rubber comb is rubbed with a piece of wool. During the process the comb acquired a \n negative electrostatic charge. Of the following statements, which is correct?
C) The comb has an excess of electrons
c
d
a
b
d
b
c
b
c
d
a
c
d
b
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Flashcard (22)