A mass of 11.0 kg , fastened to the end of an aluminum wire with an unstretched length of 0.47 m , is whirled in a vertical circle with a constant angular speed of 118 rev/min . The cross-sectional area of the wire is 2.0×10⁻² cm2 .

Part A:

Calculate the elongation of the wire when the mass is at the lowest point of the path.

Express your answer using two significant figures.

Part B:

Calculate the elongation of the wire when the mass is at the highest point of its path.

Express your answer using two significant figures.

December 21, 2012: Are we all going to die? Section: ____________ Written by: Jeremy Jones

Over the past few years, websites, books, and even a big blockbuster movie have popped up concerning the ancient Mayan "prediction" that the world will end on December 21, 2012. It is true that the 13th bak'tun of the Mayan calendar will end on December 21, 2012. So what?, the 12th month of the modern calendar ends on December 31 every year. However, the end of the 13th bak'tun is supposed to be a special occasion (similar to the year 2000 was for us, or the last year of a decade).

If that was the end of the claims proposed by these websites, books, and movies, then we could just leave it up to the historians, anthropologists and archaeologists to deal with the myths. Unfortunately, the 2012ers (all conspiracy theorists need an "ers" behind their collective name) decided they'd make a few claims pertaining to how the world is going to end. These claims delve heavily in the pseudo-science astrology (the study of how the stars and planets affect our daily life). We will take a look at a couple of these claims, namely the claim that a planetary alignment will destroy the Earth and the claim that a previously unseen planet will destroy the Earth.

Forces of Planetary Alignment

For centuries, astrologers have "known" that planetary alignments are times of great stress and disaster, so it's no surprise that it's put forward by 2012ers as one of the ways the world will end. However, no astrologer has ever come up with a scientific theory or any evidence concerning why planetary alignments are such an issue, but let's take a look at it anyway. There are four different ways that matter can interact: gravitationally, electromagnetically, and through the weak and strong nuclear forces. The two nuclear forces only work for nuclear distances, so we can drop those from consideration. The planets have no net electric charge, but some of them (including Earth) have magnetic fields. Could they be interacting? Well, no. The magnetic fields of the planets are incredibly weak, and the distances between the planets so large that they have no effect. The Sun's magnetic field interacts with the Earth's, but that won't change if you have planetary alignment.

This leaves one force to analyze, gravity. Keep this question in mind as you do this part of the lab exercise: can the gravity distribution in a planetary alignment change the Earth's orbit?

Given in the table below is the mass of 8 bodies in the solar system (the Sun and the planets that aren't Earth). Also given is the distance from Earth to these different bodies when the planets are all aligned.

In the table above, calculate R2 and F for each body. The force of gravity between a body of mass M and the

Earth is Fgrav=(3.98x10^20) (M/R^2) (R is the distance from the Earth to that body when the planets are aligned) R2

The index of refraction for violet light in silica flint glass is 1.66, and that for red light is 1.62. What is the angular spread of visible light passing through a prism of apex angle 60.0

A uniform cylinder of radius 11 cm and mass 24 kg is mounted so as to rotate freely about a horizontal axis that is parallel to and 4.6 cm from the central longitudinal axis of the cylinder. (a) What is the rotational inertia of the cylinder about the axis of rotation? (b) If the cylinder is released from rest with its central longitudinal axis at the same height as the axis about which the cylinder rotates, what is the angular speed of the cylinder as it passes through its lowest position?

According to the Guinness Book of World Records, the longest home run ever measured was hit by Roy

2.) Explain why a star ceases to contract when the deBroglie wavelength of its electrons approximately
    equals the average distance between electrons.

A 65 kg woman stands at the rim of a horizontal turntable having a moment of inertia of 520 kg·m² and a radius of 2.0 m. The turntable is initially at rest and is free to rotate about a frictionless vertical axle through its center. The woman then starts walking around the rim clockwise (as viewed from above the system) at a constant speed of 1.5 m/s relative to the Earth.

(a) In what direction and with what angular speed does the turntable rotate?

counterclockwise clockwise    

2 rad/s

(b) How much work does the woman do to set herself and the turntable into motion?
3 J

A stone is dropped into a river from a bridge 43.0 m above the water. Another stone is thrown vertically down 1.44 s after the first is dropped. Both stones strike the water at the same time. What is the initial speed of the second stone?

A taut string of density p and length b is fixed at both ends. At a distance 3b/7 from the origin it is pulled up by an amount h, and at a distance 4b/7 it is pulled down by the same amount. Both points are released simultaneously.

Describe the motion and the amplitudes of the normal modes (So, which modes are not excited and why not)

In a nuclear reactor, a neutron moving at speed v in the positive x-direction strikes a deuteron, which is at rest. The neutron is deflected by 90.0

A 2.0 kg block sits on a 4.0 kg block that is on a frictionless table. The coefficients of friction between the blocks are µs = 0.80 and µk = 0.20.

(a) What is the maximum force F that can be applied to the 4.0 kg block if the 2.0 kg block is not to slide?

______N

(b) If F is half this value, find the acceleration of each block.

______m/s² (2.0 kg block)
______m/s² (4.0 kg block)

--Find the magnitude of the force of friction acting on each block.

______N (2.0 kg block)

______N (4.0 kg block)

(c) If F is twice the value found in (a), find the acceleration of each block.

______m/s2 (2 kg block)

______m/s2 (4 kg block)

The single most important use of the element gold is for wires that join integrated circuits to the conducting pads that then connect microelectronic chips with external circuitry. A typical application uses gold wires 1.0 milmil (0.001 inch) in diameter and 60 milmil long. Although the current under normal conditions is much less, such a wire will fuse (that is, melt and interrupt the current) when the current exceeds some 550 mAmA.

Find the current density in the wire when this maximum current is flowing.

Find the electric field in the wire when this maximum current is flowing.

Find the voltage between the ends of the wire when this maximum current is flowing.

1. A stone is thrown upward from a tower with initial velocity of 3 m/s. Height of tower is 50 m above the ground.

• What would be its position after 3.4 secs?
• What would be its speed after 3.4 secs?
• What would its velocity be when it hits the ground?

2. Duterte throws a ball upward at 15 m/s while standing on the edge of a building so that the ball can fall to the base of the building 50 m below. How long does it take the ball to reach the base of the building?

3. A Phil. Air Force helicopter is ascending vertically with a speed of 4.8 m/s at a height of 120 m above the earth, a package is dropped from the helicopter on a mission. How much time does it take for the package to reach the ground?

4. A ball is thrown vertically upward with an initial velocity of 3 m/s, from the window of a condominium. The ball strikes the sidewalk at the ground level 4 seconds later. Find the height of the window above the ground level.

5. A window of the new condominium at Ayala Commercial Center has a height of window “h” above the ground level. A boy throws a ball with an initial velocity of 2.8 m/s upward from the window of the building. Find the value of “h” if the ball strikes the ground 4.2 sec. later.

⁹⁸Mo(³He,d)⁹⁹Tc is the process used to produce the Tc isotope.

Calculate the Q-Value to three decimal places.

Calculate the maximum kinetic energy of the deuterium populating the ground state of Tc

Calculate the maximum kinetic energy of the deuterium populating the 0.18 MeV excited level of Tc

Calculate the maximum kinetic energy of the deuterium populating the 0.51 MeV excited level of Tc t