A 200 gram of ice block falls from a height of 80 meters onto a bucket of 1 kg water in a copper bucket of mass 100 grams. The initial temperature of the ice is 0 and the bucket and water is 20 C. Assume that 60% of the potential energy of the ice block goes into heat!!!! What is the final temperature of the ice, water and bucket mixture?? If not all the ice melts, then what is the final mass of the remaining block of ice?

Use C_cu = .092 cal/g.C, C_water = 1 cal/g.C, L_fwater = 333.55 J/gram

answer choices

a) 4.02 C

b) 61.6 grams of ice block left

c) 45.5 grams of ice block left

d) 3.53 C

e) 3.50 C

One of the particle accelator technologies is cycotron. Please explain principle contruction, working and limitations of cycotron.

Try out some of the principles of light by comparing Polaris to the sun.

a. The intensity of sunlight at a satellite in earth orbit is 1360 W/m2. What is the magnitude of the electric and magnetic field ?

b. Astronomers estimate the distance to Polaris is 431 light years and its intrinsic luminosity (energy per second) is 2200 times that of the sun. Use proportional reasoning and your answer to part a to estimate the intensity and the magnitude of the electric field at the earth. You can give it in terms of A.U., factors of earth’s distance from our sun.

c. A planet in the “habitable zone” around Polaris should receive a light intensity similar to our planet. Again use proportional reasoning to estimate what distance might be a good one.

d. The color of a star depends on temperature of the outer regions of the star. The peak wavelength for polaris is 400 nm and for the sun is 500 nm. Another famous star, Betelgeuse, has its peak wavelength at 828 nm. What color light are these specific wavelengths, and what is the frequency of this light? Actually, we perceive the first two stars to be “white” and Betelgeuse to be distinctly “red”. Explain in your own words.

   You pick up your older mobile phone to see who just sent you a text, but its dark ! Your sunglasses are blocking all pixels, all colors from your phone.

a. Aha, with a reminder from the textbook or the interwebs, you know what polarization the glare has, so you also know what polarization the light from your phone has. Explain.

b. You rotate your phone from its normal orientation by 10 degrees, then 30 degrees, then 45, then to 90 where you see its full intensity and successfully read your text. Calculate what fraction of full intensity (or equivalently what fraction of full power) makes it through your sunglasses in each case ?

c. Some energy did not make it to your eye. In the case of sunglasses, can you guess where does the energy go?

What evidence do we have that spiral arms are regions of very active star formation? Give an answer that includes both nebulae and stars. What colors do we see?

In the context of galaxies and galaxy formation, what are tidal streams, and how are they created?

By carefully measuring the velocities of stars, astronomers can graph the rotation curves of a galaxy. What does the rotation curve of our galaxy tell us about the mass of our galaxy? What mysterious substance is most of the galaxy made of, and how do we know this?

A wood burning stove is box shaped with a height of 30.7”, width 26.25” and depth 25.5”. The front surface is glass (Ԑ= 0.9) and the other surfaces are cast iron (Ԑ= 0.7). The fire keeps the stove surface at a constant 202 °C.

a.Calculate the rate at which the stove’s one glass surface (30.7” by 26.25”) radiates heat into the surrounding space.

b.Calculate the rate at which the cast iron sides radiate heat into the surrounding space. Add this to your answer to part a) to determine the total rate of radiation into the surrounding space. Assume the stove is raised off the floor so the bottom radiates.

c. If the surrounding temperature is 22 °C, find the net rate of radiative heat transfer from the wood stove to the surroundings

The figure shows an approximate plot of stress versus strain for a spider-web thread, out to the point of breaking at a strain of 2.05. The vertical axis scale is set by a = 0.130 GN/m²,b = 0.460 GN/m², and c = 0.840 GN/m². Assume that the thread has an initial length of 0.780 cm, an initial cross-sectional area of 8.00 × 10^-12 m², and (during stretching) a constant volume. The strain on the thread is the ratio of the change in the thread's length to that initial length, and the stress on the thread is the ratio of the collision force to that initial cross-sectional area. Assume also that when the single thread snares a flying insect, the insect's kinetic energy is transferred to the stretching of the thread. a) How much kinetic energy would put the thread on the verge of breaking? What is the kinetic energy of b) a fruit fly of mass 6.50 mg and speed 1.90 m/s and c) a bumble bee of mass 0.400 g and speed 0.360 m/s? Would d) the fruit fly and e) the bumble bee break the thread?

The graph shows a= 0.700, b= 1.40, c= 2.05.

When high voltage is run through hydrogen, light is emitted that is concentrated in three areas of the visible spectrum: red, cyan, and violet. How did Bohr explain this, and how did de Broglie alter that explanation to extend it to the emission spectrum of other elements?

A. A disk of radius 0.15 m spins at a rate of 18 rad/s. What is the linear speed of a point on its outer rim? How long does it take that point to make a complete revolution? What would be given as the frequency in hertz of this motion?

B. A mass and spring system is built with a spring constant of 5.0 N/m and a mass of 2 kg. What is its period of oscillation? What length would a simple pendulum have to have to make an identical mass oscillate with that same period?

3. Interference: Consider the double slit experiment conducted in lab. You now have a new double slit slide to analyze. On the wall 1.75m away from the slits, the first minima occurs 0.65 mm to the side of the central maxima when using the red laser (wavelength=633 nm).

a) Find the slit spacing.

b) If the fourth maximum (from the central maximum) is missing, what is the slit width? Be sure to justify your answer with the appropriate equation(s).

c) What is the double slit phase at the third double slit minima?

d) What is the single slit phase at the third double slit minima?

e) What is the combined intensity at the third double slit minima?

What is wave ? Differentiate between Longitudinal wave and Transverse wave. How can you generate both types of wave on a slinky? Write in detail

a) The rotational characteristic energy E_0r for the nitrogen molecule N₂ is 2.48 x 10^-4 eV. Find the bond lenght of the molecule.

b) Write the electronic configuration of this molecule.

A -3.50 nC point charge is at the origin, and a second -5.50 nC point charge is on the x-axis at x = 0.800 mm.

D) Find the net electric force that the two charges would exert on an electron placed at point on the x-axis at x = 0.200 mm. Express your answer with the appropriate units. Enter positive value if the force is in the positive x-direction and negative value if the force is in the negative x-direction.

F) Find the net electric force that the two charges would exert on an electron placed at point on the x-axis at x = -0.200 m. Express your answer with the appropriate units. Enter positive value if the force is in the positive x-direction and negative value if the force is in the negative x-direction.