AP Physics (study or your ass gonna fail this hoe)
Terms in this set (56)
Vectors 1, 2, 3, and 5
The drawing shows five displacement vectors. Which four of these vectors, when added together in a tail-to-head manner, give a resultant vector that is zero? (Hint: The resultant vector is the vector drawn from the tail of the first vector to the head of the last vector. If the resultant vector is zero, what must be true about the tail of the first vector relative to the head of the last vector?)
5.28 × 10^5 m
A spacecraft is traveling with a velocity of +3250 m/s. Suddenly the retrorockets are fired, and the spacecraft begins to slow down with an acceleration whose magnitude is 10.0 m/s2. How far does the spacecraft travel until it comes to a momentary halt?
Both balls have the same acceleration at all times.
Two balls are thrown from the top of a building, as in the drawing. Ball 1 is thrown straight down, and ball 2 is thrown with the same speed, but upward at an angle è with respect to the horizontal. Consider the motion of the balls after they are released. Which one of the following statements is true?
A space probe with its engines shut down, moving through a vast empty region of outer space.
Which one of the following objects is in equilibrium?
The centripetal forces are the same.
Two identical cars, one on the moon and one on the earth, have the same speed and are rounding banked turns that have the same radius r. There are two forces acting on each car, its weight mg and the normal force FN exerted by the road. Recall, that the weight of an object on the moon is about one sixth of its weight on earth. How does the centripetal force on the moon compare with that on earth?
APE = 0 J and AKE = 0 J
A stone is thrown with a speed v0 and returns to earth, as the drawing shows. Ignore friction and air resistance, and consider the initial and final locations of the stone. Which one of the following correctly describes the change APE in the gravitational potential energy and the change AKE in the kinetic energy of the stone as it moves from its initial to its final location?
A, B, C, and D
A toy car (0.50 kg) runs on a frictionless track and has an initial kinetic energy of 2.2 J, as the drawing shows. The numbers beneath each hill give the heights of the hills. Over which of the hills will the car coast?
They have the same kinetic energies, but different momenta.
Two identical cars are traveling at the same speed. One is heading due east and the other due north, as the drawing shows. Which statement is true regarding the kinetic energies and momenta of the cars?
4.24 kg m/s
Two arrows are fired simultaneously with the same speed of 30.0 m/s. Each arrow has a mass of 0.100 kg. One is fired due east and the other due south. What is the magnitude of the total momentum of this two-arrow system?
You are in a tall building located near the equator. As you ride an elevator from the ground floor to the top floor, your tangential speed due to the earth's rotation ____________.
A and C, but not B
A rotating object has an angular acceleration α that is not zero. Which one or more of the following three statements is consistent with a non-zero angular acceleration?
A. The angular velocity ω increases as time passes.
B. The angular velocity ω has the same value at all times.
C. The angular velocity ω decreases as time passes.
τ3, τ2, τ1 and τ4 (a two-way tie)
The drawing illustrates an overhead view of a door and its axis of rotation. The axis is perpendicular to the screen. There are four forces acting on the door, and they have the same magnitude. Rank the torque T that each force produces, largest to smallest.
Both have the same total kinetic energy.
Two hoops, starting from rest, roll down identical inclined planes. The work done by nonconservative forces, such as air resistance, is zero (Wnc = 0 J). Both have the same mass M, but, as the drawing shows, one hoop has twice the radius as the other. The moment of inertia for each hoop is I = Mr2, where r is its radius. Which, if either, has the greater total kinetic energy (translational plus rotational) at the bottom of the incline?
The amplitude remains the same, and the angular frequency increases.
A block is attached to a horizontal spring. On top of this block rests another block. The two-block system slides back and forth in simple harmonic motion on a frictionless horizontal surface. At one extreme end of the oscillation cycle, when the blocks come to a momentary halt, the top block is liften vertically upward, without disturbing the bottom block. What happens to the amplitude and the angular frequency of the ensuing motion?
Decrease A by 10% and increase ω by 10%.
An object is oscillating in simple harmonic motion with an amplitude A and an angular frequency ω. What should you do to increase the maximum acceleration of the motion?
It is less at higher temperatures than at lower temperatures.
What happens to the Doppler effect in air (i.e., the shift in frequency of a sound wave) as the temperature increases?
both the condensations and the rarefactions of the wave disappear.
As the amplitude of a sound wave in air decreases to zero, _________________.
A cylindrical bottle, partially filled with water, is open at the top. When you blow across the top of the bottle a standing wave is set up inside it. If you take a sip from the bottle, is the fundamental frequency of the standing wave raised, lowered, or does it remain the same?
A, B, C
A single resistor is connected across the terminals of a battery. Which one or more of the following changes in voltage and current leaves unchanged the electric power dissipated in the resistor?
(A) Doubling the voltage and reducing the current by a factor of two.
(B) Doubling the voltage and increasing the resistance by a factor of four.
(C) Doubling the current and reducing the resistance by a factor of four.
For the circuit shown in the drawing, what is the voltage V1 across resistance R1?
The velocity is zero at one instant, and the acceleration is not zero at that instant.
Only one of the following is possible for a moving object. Which one?
Both projectiles are in the air for the same amount of time.
Two objects are fired into the air. The drawing shows that they reach the same height, but the ranges of their projectile motions are different. Which one is in the air for the greatest amount of time?
The drawing shows a block at rest on an incline. The mass of the block is 8.0 kg. What is the static frictional force that acts on the block?
2, 1, 3
The drawing shows an extreme skier at three locations on a ski run: (A) a straight section, (B) a circular section, and (C) an airborne phase in which the skier is in free-fall. At the right of the drawing are four possible directions for the net force that acts on the skier. What is the direction of the net force at A, B, and C? Assume that there is no friction or air resistance at any point along the ski run.
The kinetic energy, speed, and velocity of the particle change.
A nonzero net force acts on a particle and does work. Which one of the following statements is true?
Consider the force F shown in the drawing. This force acts on an object that can move along the positive or negative x axis, or along the positive or negative y axis. The work done by this force is positive when the displacement of the object is along the __________ axis or along the __________ axis.
Object 1 is moving along the x axis with an initial momentum +16 kg·m/s, where the + sign indicates that it is moving to the right. As the drawing shows, object 1 collides with a second object that is initially at rest. The collision is not head-on, so the objects move off in different directions after the collision. The net external force acting on the two-object system is zero. After the collision, object 1 has a momentum whose y component is -5 kg·m/s. What is the y-component of the momentum of object 2 after the collision?
The air mattress exerts the same impulse, but a smaller net average force, on the high-jumper than does the hard ground.
A high-jumper, having just cleared the bar, lands on an air mattress and comes to rest. Had she landed directly on the hard ground, her stopping time would have been much shorter. Using the impulse-momentum theorem as your guide, determine which one of the following statements is correct.
A merry-go-round at a playground is a circular platform that is mounted parallel to the ground and can rotate about an axis that is perpendicular to the platform at its center. The angular speed of the merry-go-round is constant, and a child at a distance of 1.4 m from the axis has a tangential speed of 2.2 m/s. What is the tangential speed of another child, who is located at a distance of 2.1 m from the axis?
1.2 × 10^3 revolutions
The radius of each wheel on a bicycle is 0.400 m. The bicycle travels a distance of 3.0 km. Assuming that the wheels do not slip, how many revolutions does each wheel make?
Each external torque may be non-zero, but the sum of the torques must be zero.
Under what condition(s) is the angular momentum of a rotating body, such as a spinning ice skater, conserved?
The object with the greater mass should be attached to the spring with the smaller spring constant.
You have two springs. One has a greater spring constant than the other. You also have two objects, one with a greater mass than the other. Which object should be attached to which spring, so that the resulting spring-object system has the greatest possible period of oscillation?
vA = maximum, aA = 0 m/s2, vB = 0 m/s, aB = maximum
The drawing shows a graph of displacement x versus time t for simple harmonic motion of an object on a horizontal spring. Which one of the following answers correctly gives the magnitude v of the velocity and the magnitude a of the acceleration at points A and B in the graph?
The frequency in the air is the same as the frequency in the water, and the wavelength in the air is smaller than the wavelength in the water.
A horn on a boat sounds a warning, and the sound penetrates the water. How does the frequency of the sound in the air compare to its frequency in the water? How does the wavelength in the air compare to the wavelength in the water?
The following four equations are supposed to result from applying Kirchhoff's junction rule to the four junctions in the circuit shown in the drawing. However, one of the equations is written incorrectly. Which one is it?
B, C, A
In the following three arrangements each resistor has the same resistance R. Rank the equivalent resistances of the arrangements in descending order (largest first).
The drawing shows two displacements, 3.0 km due north and 4.0 km due east, and the corresponding resultant vector R. What is the angle è that R makes with respect to due north?
Both balls have the same vertical component.
Ball 1 is thrown into the air and it follows the trajectory for projectile motion shown in the drawing. At the instant it is at the top of its trajectory, Ball 2 is dropped from rest at the same height. Just before they reach the ground, the velocity of Ball 1 has a horizontal component vx and a vertical component vy. Ball 2 only has a vertical component. Which ball has the greater vertical component?
A small cylinder rests on a circular turntable that is rotating clockwise at a constant speed. Which set of vectors gives the direction of the velocity v and acceleration a of the cylinder, and the net force ÓF that acts on it.
A hot-air balloon is 11.0 m above the ground and rising at a speed of 7.00 m/s. A ball is thrown horizontally from the balloon basket at a speed of 9.00 m/s. Ignore friction and air resistance and find the speed of the ball when it strikes the ground.
A person is riding on a Ferris wheel. When the wheel makes one complete turn, the net work done on the person by the gravitational force ____________.
Two objects undergo an elastic collision. The table shows four possible sets of the initial and final kinetic energies of the objects. Which is the only set that could occur?
The moon is 3.85 × 108 m from the earth and has a diameter of 3.48 × 106 m. You have a pea (diameter = 0.50 cm) and a dime (diameter = 1.8 cm). Close one eye and hold each object at arm's length (71 cm) between your open eye and the moon. Which objects, if any, completely cover your view of the moon? Assume that the moon and both objects are sufficiently far from your eye that the given diameters are equal to arc lengths when calculating angles.
The box will have an angular acceleration, but not a translational acceleration.
The drawing shows a top view of a square box lying on a frictionless floor. Three forces, which are drawn to scale, act on the box. Consider an angular acceleration with respect to an axis through the center of the box (perpendicular to the screen). Which one of the following statements is correct?
larger, because her angular speed is larger.
An ice skater is spinning on frictionless ice with her arms extended outward. She then pulls her arms in toward her body, reducing her moment of inertia. Her angular momentum is conserved, so as she reduces her moment of inertia, her angular velocity increases and she spins faster. Compared to her initial rotational kinetic energy, her final rotational kinetic energy is _________
KE is has a maximum value at position 2. EPE has a maximum value at position 3. GPE has a maximum value at position 1.
The drawing shows an object attached to an ideal spring, which is hanging from the ceiling. The unstrained length of the spring is indicated. For purposes of measuring the heighth that determines the gravitational potential energy, the floor is taken as the position where h = 0 m. The equilibrium position at which the object hangs stationary is identified as position 2. The object is set into vertical simple harmonic motion between positions 1 and 3. Identify the positions where the kinetic energy KE, the elastic potential energy EPE, and the gravitational potential energy GPE each have their maximum values during an oscillation cycle.
at different times, the echo under water returning more quickly.
An echo is sound that returns to you after being reflected from a distant surface (e.g., the side of a cliff). Assuming that the distances involved are the same, an echo under water and an echo in air return to you _____________________.
A wind instrument is brought into a warm house from the cold outdoors. What happens to the natural frequencies of the instrument? Neglect any change in the length of the instrument.
Two wires are made from the same material. One wire has a resistance of 0.10 Ω. The other wire is twice as long as the first wire and has a radius that is half as much. What is the resistance of the second wire?
4.0 km/h, due north
A boat moves 3.0 km due north and then moves 1.0 km due south. The time for this trip is half an hour. What is the average velocity of the boat?
B, C, A
A heavy block is suspended from a ceiling using pulleys in three different ways, as shown in the drawings. Rank the tension in the rope that passes over the pulleys in ascending order (smallest first).
1, 2, 3
Three particles have the following masses (in multiples ofm0) and move on three different circles with the following speeds (in multiples of v0) and radii (in multiples of r0):
A 3.00-kg model airplane has velocity components of 5.00 m/s due east and 8.00 m/s due north. What is the plane's kinetic energy?
A and E
Six runners have masses (in multiples of m0), speeds (in multiples of v0) and travel in the directions indicated in the table. Which two runners have identical momenta?
A rotating wheel has a constant angular acceleration. It has an angular velocity of 5.0 rad/s at time t = 0 s, and 3.0 s later has an angular velocity of 9.0 rad/s. What is the angular displacement of the wheel during the 3.0-s interval?
The smaller hoop; two times as great.
The same force F is applied to the edge of two hoops. The hoops have the same mass, although the radius of the larger hoop is twice that of the smaller one. The entire mass of each hoop is concentrated at its rim, so the moment of inertia is I = Mr2, where M is the mass and r is the radius. Which hoop has the greater angular acceleration, and how many times as great is it compared to that of the other hoop?