Answer questions 1-3 with clockwise, counterclockwise, or zero. Show your work.

1. A loop of wire is oriented horizontally, so that a vector normal to the loop is oriented downward. An external magnetic field is directed due west, at an angle of 14° above the horizontal. The magnitude of the field is decreasing over time. As viewed from above, the induced current is:

2. ____________________

3. A loop of wire is oriented horizontally, so that a vector normal to the loop is oriented upward. An external magnetic field is directed northeast, at an angle of 34° above the horizontal. The magnitude of the field is increasing over time. As viewed from above, the induced current is:

   ____________________

4. A loop of wire is oriented vertically, so that a vector normal to the loop is oriented to the east. An external magnetic field is directed east. The loop begins to rotate around a vertical rotation axis. As viewed from the east, the induced current is:

   ____________________

5. A circular loop of radius 1.79 m is mounted on top of a truck. Initially the truck is at rest oriented so that a vector normal to the loop points north. At this location, the Earth’s magnetic field has a magnitude of 49.6 μT and a direction of due north, 63° below the horizontal.

1. Over the course of 9.0 seconds, the truck accelerates north, so that at the end of the time interval, the truck is moving at 14.0 m/s north. Find the magnitude of the average induced emf in the loop during this time interval and the direction of the induced current, as viewed from the south.

   ६ Ind = ____________________ direction of Iind = ____________________

2. Over the course of the next 5.0 seconds, the truck turns, so that at the end of the time interval, the truck is moving at 14.0 m/s east. Find the magnitude of the average induced emf in the loop during this time interval and the direction of the induced current, as viewed from the east.

   ६ Ind = ____________________ direction of Iind = ____________________

IP A soccer ball is kicked with an initial speed of 10.8 m/s in a direction 26.0 ∘ above the horizontal.

a) Find the magnitude of its velocity 0.250 s after being kicked.

b) Find the direction of its velocity 0.250 s after being kicked.

c) Find the magnitude of its velocity 0.500 s after being kicked.

d) Find the direction of its velocity 0.500 s after being kicked.

e) Is the ball at its greatest height before or after 0.500 s ? before or after

A ceiling fan with 90-cm-diameter blades is turning at 68 rpm . Suppose the fan coasts to a stop 29 s after being turned off.

part A) What is the speed of the tip of a blade 10 s after the fan is turned off?

part B) Through how many revolutions does the fan turn while stopping?

Bowling balls can be made from a variety of substances and are required to have a circumference of roughly 27.4 inches. The construction of the ball typically consists of a high density core surrounded by a lower density shell. Suppose a bowling ball floats in water with half of its volume submerged. If the specific gravity of the shell is 0.350 and the specific gravity of the core is 0.800, calculate the thickness of the shell.

How much heat is required to convert 12.0 g of ice at-10.0 degrees C to steam at100.0 degrees C ? Express your answer in joules and in calories.

Although gas station owners lock their tanks at night, a gas station owner in your neighborhood was the victim of theft because his employee had a key to the tank. The owner of the gas station wants to bury the gasoline so deep that no vacuump pump, no matter how powerful, will be able to extract it. He has hired you as a general contractor to dig the holes for the tanks. What is the minimum depth needed for the surface of the gasoline to be unsiphonable? Assume the specific gravity of gasoline is 0.744. (You can ignore the drop rate of the gasoline level inside the tank.)

The gas station owner balks at your estimate. He neither has the funds nor approval from the city to dig that deeply. However, you tell him that the best a thief could hope to have at his disposal is a 194-mbar vacuum pump. Anything better would be enormously expensive. Given this information, how deep would the gasoline have to sit below the surface to keep it safe from thieves?

A 1.30 kg , horizontal, uniform tray is attached to a vertical ideal spring of force constant 200 N/mand a 275 g metal ball is in the tray. The spring is below the tray, so it can oscillate up-and-down. The tray is then pushed down 13.3 cm below its equilibrium point (call this point A) and released from rest.

A) How high above point A will the tray be when the metal ball leaves the tray? (Hint: This does not occur when the ball and tray reach their maximum speeds.) B)How much time elapses between releasing the system at point A and the ball leaving the tray? c)How fast is the ball moving just as it leaves the tray?

a. How long (in s) would it take a 1.50 ✕ 105 kg airplane with engines that produce of 100 MW of power to reach a speed of 300 m/s and an altitude of 12.0 km if air resistance were negligible? b. If it actually takes 850 s, what is the power applied, in megawatts? c. Given this power, what is the average force (in kN) of air resistance if the airplane takes 1200 s? (Hint: You must find the distance the plane travels in 1200 s assuming constant acceleration.)

For lunch, you and your friends decide to stop at the nearest deli and have a sandwich made fresh for you with 0.103 kg of turkey. The slices of turkey are weighed on a plate of mass 0.430 kg and placed atop a vertical spring of negligible mass, with a force constant of k = 170 N/m. The slices of turkey are dropped on the plate all at the same time from a height of 0.310 m. They make a totally inelastic collision with the plate and set the scale into vertical simple harmonic motion (SHM). You may assume that the collision time is extremely small. Once the turkey is on the plate, the scale oscillates around a new equilibrium position. a. How far from the new equilibrium position was the plate when the slices of turkey landed on it? b. Find the velocity of the turkey immediately after the collision.

Problem 21: A uniform stationary ladder of length L = 3.7 m and mass M = 19 kg leans against a smooth vertical wall, while its bottom legs rest on a rough horizontal floor. The coefficient of static friction between floor and ladder is μ = 0.44. The ladder makes an angle θ = 56° with respect to the floor. A painter of mass 8M stands on the ladder a distance d from its base.

Part (a) Find the magnitude of the normal force N, in newtons, exerted by the floor on the ladder. Numeric : A numeric value is expected and not an expression. N = __________________________________________

Part (b) Find an expression for the magnitude of the normal force NW exerted by the wall on the ladder. MultipleChoice: 1) NW = ½Mg cot? 2) NW = 1/2Mg cot? (1+16d/L) 3) NW = 1/2Mg cot? (16d/L) 4) NW = 1/2Mg tan? (1+16d/L) 5) NW = Mg cot? (16+d/2L)

Part (c) What is the largest distance up the ladder dmax, in meters, that the painter can stand without the ladder slipping? Numeric : A numeric value is expected and not an expression. dmax = __________________________________________

A parallel-plate capacitor has capacitance C0 = 7.80 pF when there is air between the plates. The separation between the plates is 1.80 mm.

1- What is the maximum magnitude of charge that can be placed on each plate if the electric field in the region between the plates is not to exceed 3.00×10⁴ V/mV/m?

Express your answer with the appropriate units.

2- A dielectric with KKK = 2.40 is inserted between the plates of the capacitor, completely filling the volume between the plates. Now what is the maximum magnitude of charge on each plate if the electric field between the plates is not to exceed 3.00×10⁴ V/mV/m?

Express your answer with the appropriate units.

A large grinding wheel in the shape of a solid cylinder of radius 0.330 m is free to rotate on a frictionless, vertical axle. A constant tangential force of 300 N applied to its edge causes the wheel to have an angular acceleration of 0.894 rad/s².

(a) What is the moment of inertia of the wheel?



(b) What is the mass of the wheel?


(c) If the wheel starts from rest, what is its angular velocity after 4.90 s have elapsed, assuming the force is acting during that time?

I'm working on a post against a recent creationism article about blue stragglers. From when I was in undergrad, the general explanation was that they were likely second generation stars within globular clusters. More recent work seems to indicate that it's likely due to binary interactions with a sun-like star siphoning material off a companion to become a recent and short-lived blue supergiant.

Since this is way outside my field, I thought I'd try my luck here and get a bronze badge because I've never asked a question. What are the most accepted theories these days for this phenomenon?

You walk into a room and notice that there someone is running an experiment involving a spring-mass system. You have no idea when the experiment started, but observe that the mass attached to the spring is oscillating with period 3 (seconds) and that the amplitude of the oscillations remain constant (to your naked eye) while you are in the room. What are two differential equations which model the motion of the mass? One system must be inhomogeneous and the other must be homogeneous. Do not worry about the initial conditions.