As our Sun ages, it will go through a period of collapse. If we take the maximum possible density of any material in the universe to be that of neutron stars which have densities around 1017kg/m3, is it possible that our sun could collapse to form a black hole? What is the minimum mass of an object that could potentially form a black hole if it collapses to have the same density as a neutron star? (express your answer as a multiple of the solar mass)

An object is solid throughout. When the object is completely submerged in ethyl alcohol, its apparent weight is 15.9 N. When completely submerged in water, its apparent weight is 13.4 N. What is the volume of the object?

Consider a person standing on a bathroom scale. Draw a free body diagram for the person and draw one for the scale. For each force you identified on the person name the other object with which the person is interacting.

An ice cube of volume 15 cm³ is initially at the temperature -20C . How much heat is required to convert this ice cube into steam?

1. (a) What drives current? (b) What impedes current? (c) How does Ohm’s Law relate these quantities?
2. Why isn’t Ohm’s Law universally valid?
3. What is the resistance of an automobile headlight through which 3.50 A flows when 12.0 V is applied to it?
4. If a battery supplies energy to a circuit, what does the resistor do with that energy?
5. Calculate the effective resistance of a pocket calculator that has a 6.2 V battery and through which 0.20 mA flows.

An airplane is flying at a constant horizontal velocity of 184.5 m/s and drops a rocket. The rocket falls for 10.24 s without air resistance and under the influence of gravity only, and then fires its thrusters. From the moment the thrusters are one, the rocket has a net acceleration of 5.481 direscted 30.21 degrees above the horizontal. How far apart are the plane and the rocket when the rocket passes back through the cruising altitude of the plane?

why do you feel weightless in the International Space station?

An older-model car accelerates from 0 to speed v in a time interval of ?t. A newer, more powerful sports car accelerates from 0 to 2v in the same time period. Assuming the energy coming from the engine appears only as kinetic energy of the cars, compare the power of the two cars.

A monatomic ideal gas is contanined in a cylinder with a moveable piston. Initially the volume of the cylinder is 0.25m^3. The gas is compressed under a constant pressure of 3 Pa until the volume has been halved. Then the volume is held constant while the pressure is doubled. Finally, the gas is allowed to expand isothermally back to its original condition.

a)Sketch a P-V diagram for this process. Label the corners 1, 2, 3 with 1 being the beginning point.

b) If the temperature was 27 degrees at the beginning, what was the temperature at the end of the isobaric process?

c) how many moles of gas are there? How many particles of gas are there?

d) what is the total thermal energy of the system at the beginning of the process?

e) Find the work, heat and change in thermal energy for each step of the process. Place your final answers in a chart.

I got part b by using Tfinal=Tinitial*(Vfinal/Vinital)= 150K but am not getting the correct answers for the rest part c I know I use n=pV/RT but for some reason not coming up with the correct answer. Please Help???

An attacker at the base of a castle wall 3.75 m high throws a rock straight up with speed 8.50 m/s from a height of 1.60 m above the ground.

(a) what is the rock speed at the top? ?

m/s

(b) Find the change in speed of a rock thrown straight down from the top of the wall at an initial speed of 8.50 m/s and moving between the same two points.

?m/s

(c) Does the change in speed of the downward-moving rock agree with the magnitude of the speed change of the rock moving upward between the same elevations? Explain physically why it does or does not agree.

. A 0.56-kg ball is thrown vertically upward with an initial speed of 15.5 m/s. What is the speed of the ball when it has travelled one-half of the distance to its maximum height?

A 0.408 kg pendulum bob passes through the lowest part of its path at a speed of 2.71 m/s. What is the tension in the pendulum cable at this point if the pendulum is 86.8 cm long? A.) When the pendulum reaches its highest point, what angle does the cable make with the vertical? B.) What is the tension in the pendulum cable when the pendulum reaches its highest point?

An electron beam moves toward a cathode ray tube screen, which is 50 cm away from the negative electrode. The electrons are accelerated by a potential difference of 18 kV. Estimate the maximum displacement of the electron beam caused by Earth's magnetic field. The average magnetic field at the surface of Earth is roughly BE = 45×10−6T. Δz = ?

Describe stress, strain, and elastic deformation, and give example

You wish to make a model showing how traffic flows around your city or local area. Describe the steps you would take to construct your model as well as some hypotheses that your model could test and the model’s limitations in terms of what could not be tested.