Exam 1: A: Foundations

The cube of insulating material shown in the figure has one corner at the origin.Each side of the cube has length 0.080 m so the top face of the cube is parallel to the xz-plane and is at y = 0.080 m.It is observed that there is an electric field that is in the +y direction and whose magnitude depends only on y.Use Gauss's law to calculate the net charge enclosed by the cube. (ε₀ = 8.85 × 10^-12 C²/N • m²)

A planet has two small satellites in circular orbits around the planet. The first satellite has a period 12.0 hours and an orbital radius 6.00 × 10⁷ m. The second planet has a period 16.0 hours. What is the orbital radius of the second satellite?

The figure shows three long,parallel current-carrying wires.The magnitudes of the currents are equal and their directions are indicated in the figure.Which of the arrows drawn near the wire carrying current 1 correctly indicates the direction of the magnetic force acting on that wire?

A 615 N student standing on a scale in an elevator notices that the scale reads 645 N.From this information,the student knows that the elevator must be moving

An airplane flying faster than the speed of sound of 340 m/s produces a shock wave that makes an angle of 50° with the direction the plane is flying.What is the speed of the plane?

A child throws a ball with an initial speed of 8.00 m/s at an angle of 40.0° above the horizontal.The ball leaves her hand 1.00 m above the ground and experience negligible air resistance. (a) How far from where the child is standing does the ball hit the ground? (b) How long is the ball in flight before it hits the ground?

A marathon is 26 mi and 385 yd long.Estimate how many strides would be required to run a marathon.Assume a reasonable value for the average number of feet/stride.

Observer A is 3.0 m from a tiny light bulb and observer B is 12.0 m from the same bulb.Assume that the light spreads out uniformly and undergoes no significant reflections or absorption.If observer B sees a light of intensity I,the light intensity that A sees is

Three objects are connected by massless wires over a massless frictionless pulley as shown in the figure.The tension in the wire connecting the 10.0-kg and 15.0-kg objects is measured to be 133 N.What is the tension in wire A?

In the figure,the horizontal lower arm has a mass of 2.8 kg and its center of gravity is 12 cm from the elbow joint pivot.How much force F_M must the vertical extensor muscle in the upper arm exert on the lower arm to hold a 7.5 kg shot put?

What is the period (in hours)of a satellite circling Mars 100 km above the planet's surface? The mass of Mars is 6.42 × 10²³ kg,its radius is 3.40 × 10⁶ m,and G = 6.67 × 10^-11 N • m²/kg².

A 910-kg object is released from rest at an altitude of 1200 km above the north pole of the earth.If we ignore atmospheric friction,with what speed does the object strike the surface of the earth? (G = 6.67 × 10^-11 N • m²/kg²,M_earth = 5.97 × 10²⁴ kg,the polar radius of the earth is 6357 km)

A 1000-kg car approaches an intersection traveling north at 20.0 m/s. A 1200-kg car approaches the same intersection traveling east at 22.0 m/s. The two cars collide at the intersection and lock together. Ignoring any external forces that act on the cars during the collision,what is the velocity of the cars immediately after the collision?

You walk 53 m to the north,then turn 60° to your right and walk another 45 m.Determine the direction of your displacement vector.Express your answer as an angle relative to east.

What is the magnitude of the cross product of a vector of magnitude 2.00 m pointing east and a vector of magnitude 4.00 m pointing 30.0° west of north?

Two identical ladders are 3.0 m long and weigh 600 N each.They are connected by a hinge at the top and are held together by a horizontal rope,1.0 m above the smooth floor forming a symmetric "A" arrangement.The angle between the ladders is 60° and both ladders have their center of gravity at their midpoint.What is the tension in the rope?

An ideal reversible refrigerator keeps its inside compartment at 9.0°C.What is the high temperature,T_h,needed to give this refrigerator a coefficient of performance of 3.7?

A spaceship is moving between two distant stars at 0.932c.To someone in the ship,the distance between the two stars appears to be 26.9 light-years (ly).What is the distance between the stars in the rest frame of the stars?

In the figure,two identical springs have unstretched lengths of 0.25 m and spring constants of 300 N/m.The springs are attached to a small cube and stretched to a length L of 0.36 m as in Figure A.An external force P pulls the cube a distance D = 0.020 m to the right and holds it there.(See Figure B.)The work done by the external force P in pulling the cube 0.020 m is closest to

A charged capacitor stores energy U.Without connecting this capacitor to anything,dielectric having dielectric constant K is now inserted between the plates of the capacitor,completely filling the space between them.How much energy does the capacitor now store?