Exam 1: A: Foundations

Three very long,straight,parallel wires each carry currents of 4.00 A,directed out of the page as shown in the figure.The wires pass through the vertices of a right isosceles triangle of side 2.00 cm.What is the magnitude of the magnetic field at point P at the midpoint of the hypotenuse of the triangle?

A uniform solid cylindrical log begins rolling without slipping down a ramp that rises 28.0° above the horizontal.After it has rolled 4.20 m along the ramp,what is the magnitude of the linear acceleration of its center of mass?

In the figure,a laser positioned on a ship is used to communicate with a small two-man research submarine resting on the bottom of a lake.The laser is positioned 12 m above the surface of the water,and it strikes the water 20 m from the side of the ship.The water is 76 m deep and has an index of refraction of 1.33.How far horizontally is the submarine from the side of the ship?

An electron enters a magnetic field of 0.75 T with a velocity perpendicular to the direction of the field.At what frequency does the electron traverse a circular path? (m_el = 9.11 × 10^-31 kg,e = 1.60 × 10^-19C)

Shown below are the velocity and acceleration vectors for a person in several different types of motion.In which case is the person slowing down and turning to his right?

A 200 g hockey puck is launched up a metal ramp that is inclined at a 30° angle.The coefficients of static and kinetic friction between the hockey puck and the metal ramp are μ_s = 0.40 and μ_k = 0.30,respectively.The puck's initial speed is 4.9 m/s.What speed does it have when it slides back down to its starting point?

For general projectile motion,when the projectile is at the highest point of its trajectory

A lens is designed to work in the visible,near-infrared,and near-ultraviolet.The best resolution of this lens from a diffraction standpoint is

At a distance of 2.00 m from a point source of sound,the intensity level is 80.0 dB.What will be the intensity level at a distance of 4.00 m from this source? The lowest detectable intensity is 1.0 × 10^-12 W/m².

An ideal air-filled parallel-plate capacitor has round plates and carries a fixed amount of equal but opposite charge on its plates.All the geometric parameters of the capacitor (plate diameter and plate separation)are now DOUBLED.If the original energy stored in the capacitor was U₀,how much energy does it now store?

A horizontal disk rotates about a vertical axis through its center.Point P is midway between the center and the rim of the disk,and point Q is on the rim.If the disk turns with constant angular velocity,which of the following statements about it are true? (There may be more than one correct choice.)

A very large sheet of a conductor carries a uniform charge density of 4.00 pC/mm² on its surfaces.What is the electric field strength 3.00 mm outside the surface of the conductor? (ε₀ = 8.85 × 10^-12 C²/N • m²)

A graph of the force on an object as a function of its position is shown in the figure. Determine the amount of work done by this force on the object during a displacement from x = -2.00 m to x = 2.00 m.(Assume an accuracy of 3 significant figures for the numbers on the graph.)

Two weights are connected by a massless wire and pulled upward with a constant speed of 1.50 m/s by a vertical pull P.The tension in the wire is T (see figure).Which one of the following relationships between T and P must be true?

A 7.0-kg rock is subject to a variable force given by the equation F(x)= 6.0 N - (2.0 N/m)x + (6.0 N/m²)x² If the rock initially is at rest at the origin,find its speed when it has moved 9.0 m.

A small planet having a radius of 1000 km exerts a gravitational force of 100 N on an object that is 500 km above its surface.If this object is moved 500 km farther from the planet,the gravitational force on it will be closest to

The figure shows the displacement y of a traveling wave at a given position as a function of time and the displacement of the same wave at a given time as a function of position. How fast is the wave traveling?

A rocket is moving at 1/4 the speed of light relative to Earth.At the center of this rocket,a light suddenly flashes.To an observer at rest in the rocket

The graph in the figure shows the variation of the electric potential V(x)(in arbitrary units)as a function of the position x (also in arbitrary units).Which of the choices below correctly describes the orientation of the x-component of the electric field along the x-axis?

At what temperature would the root-mean-square speed (thermal speed)of oxygen molecules be 13.0 m/s? Assume that oxygen approximates an ideal gas.The mass of one O₂ molecule is 5.312 × 10^-26 kg.The Boltzmann constant is 1.38 × 10^-23 J/K.