Exam 1: A: Foundations

A 8.0-m long wire with a mass of 10 g is under tension.A transverse wave for which the frequency is 570 Hz,the wavelength is 0.10 m,and the amplitude is 3.7 mm is propagating on the wire.The maximum transverse acceleration of a point on a wire is closest to

Two objects are thrown from the top of a tall building and experience no appreciable air resistance.One is thrown up,and the other is thrown down,both with the same initial speed.What are their speeds when they hit the street?

Two objects having masses m₁ and m₂ are connected to each other as shown in the figure and are released from rest.There is no friction on the table surface or in the pulley.The masses of the pulley and the string connecting the objects are completely negligible.What must be true about the tension T in the string just after the objects are released?

A 310-g air track cart is traveling at 1.25 m/s and a 260-g cart traveling in the opposite direction at 1.33 m/s.What is the speed of the center of mass of the two carts?

An object has a position given by = [2.0 m + (3.00 m/s)t] + [3.0 m - (2.00 m/s²)t²] ,where all quantities are in SI units.What is the magnitude of the acceleration of the object at time t = 2.00 s?

Two long parallel wires placed side-by-side on a horizontal table carry identical size currents in opposite directions.The wire on your right carries current toward you,and the wire on your left carries current away from you.From your point of view,the magnetic field at the point exactly midway between the two wires

A solid uniform sphere of mass 1.85 kg and diameter 45.0 cm spins about an axle through its center.Starting with an angular velocity of 2.40 rev/s,it stops after turning through 18.2 rev with uniform acceleration.The net torque acting on this sphere as it is slowing down is closest to

A multiloop circuit is shown in the figure.It is not necessary to solve the entire circuit.The current I₂ is closest to

The second law of thermodynamics leads us to conclude that

A Carnot engine operates between reservoirs at 550K and 300K,discarding 1500 J of heat in each cycle. (a)What is the engine's efficiency? (b)How much heat is supplied to the engine by the hot reservoir in each cycle?

Suppose a region of space has a uniform electric field,directed towards the right,as shown in the figure.Which statement about the electric potential is true?

An object drops a distance h in a time of 6.3 s on the surface of the earth (neglecting air effects).How long would it take the same object to drop the same distance on the surface of spherical asteroid X having a mass of 1.1 × 10²² kg and a radius of 4.0 × 10⁵ m? (G = 6.67 × 10^-11 N • m²/kg²,M_earth = 5.97 × 10²⁴ kg,R_earth = 6.38 × 10⁶ m)

A construction worker pulls a box of tools on a smooth horizontal floor with a force of 100 N in a direction of 37.0° above the horizontal. The mass of the box and the tools is 40.0 kg. (a) Draw a free-body diagram for the box. (b) Calculate the acceleration of the box. (c) How hard does the floor push up on the box?

You slam on the brakes of your car in a panic,and skid a certain distance on a straight,level road. If you had been traveling twice as fast,what distance would the car have skidded,under identical conditions?

Wire is wound on a square frame,30 cm by 30 cm,to form a coil of 7 turns.The frame is mounted on a horizontal shaft through its center (perpendicular to the plane of the diagram),as shown in the figure.The coil is in clockwise rotation,with a period of 0.060 s.A uniform,horizontal,magnetic field of magnitude 0.40 T is present.At a given instant,the plane of the coil forms a 60° angle with the horizontal,as shown.At that instant,what is the magnitude of the emf induced in the coil?

A crate is sliding down an inclined ramp at a constant speed of 0.55 m/s.The vector sum of all the forces acting on this crate must point down the ramp.

You and your surfing buddy are waiting to catch a wave a few hundred meters off the beach. The waves are conveniently sinusoidal,and you notice that when you're on the top of one wave and moving toward your friend,she is exactly halfway between you and the trough of the wave. 1.50 seconds later,your friend is at the top of the wave.You estimate the horizontal distance between you and your friend at 8.00 m. (a)What is the frequency of the waves? (b)Find the speed of the waves.

In a two-slit experiment,the slit separation is 3.00 × 10^-5 m.The interference pattern is recorded on a flat screen-like detector that is 2.00 m away from the slits.If the seventh bright fringe on the detector is 10.0 cm away from the central fringe,what is the wavelength of the light passing through the slits?

A 6.0-m wire with a mass of 50 g,is under tension.A transverse wave,for which the frequency is 810 Hz,the wavelength is 0.40 m,and the amplitude is 4.0 mm,is propagating on the wire.The time for A crest of this wave to travel the length of the wire is closest to

The figure shows two 1.0 kg-blocks connected by a rope.A second rope hangs beneath the lower block.Both ropes have a mass of 250 g.The entire assembly is accelerated upward at 2.3 m/s² by force .What is the tension at the top end of rope 1?