Suppose that 300.0 *J* of heat is transferred by
conduction from a heat reservoir at a temperature of 415.0
*K* to another reservoir. Calculate the entropy change if
the temperature of the second reservoir is 100.0 K

In: Physics

A 27 N-m torque is applied to a flywheel that rotates about a fixed axis. The flywheel has a moment of inertia of 33 kg/m2. If the flywheel is initially at rest, what is its angular velocity in rad/s after it has turned through 5 revolutions?

In: Physics

What fraction of polystyrene is submerged when it floats in freshwater, given the density of water at 0°C is very close to 1000 kg/m3?

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An adventurous archaeologist crosses between two rock cliffs by
slowly going hand over hand along a rope stretched between the
cliffs. He stops to rest at the middle of the rope. The rope will
break if the tension in it exceeds 3.00×10^{4} N. Our
hero’s mass is 85.0 kg. Part A: If the angle θ is 13.0 ∘, find the
tension in the rope (answer in form T= ? N. Part B: What is the
smallest value the angle θ can have if the rope is not to
break?

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A 6.00-kg point mass and a 15.0-kg point mass are held in
place 1.00 m apart. A point particle of mass m = 1.00 kg is
released from a point between the two masses such that the net
gravitational force on this particle is zero. Call the line
connecting all the masses x-axis.

a. Find the center of mass of this system.

b. Find the exact position of this point mass.

c. Calculate potential energy of this system.

d. If the 6.00-kg mass is then removed and m is allowed to
orbit the 15.0-kg mass, calculate (i) the gravitational
acceleration due to the 15.0-kg mass at the location of m, (ii) the
centripetal acceleration of m (hint: how does the centripetal
acceleration relate to the gravitational acceleration?), (iii) the
period of its revolution around the 15.0-kg mass, assuming that it
stays at the same distance away from the 15.0-kg mass, and (iv) the
orbital speed of m around the 15.0-kg mass.

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**14. Boltzman's constant is equal to 1.38 x 10-23 J/ K.
Hydrogen gas molecules have a mass of 3.35 x 10-27 kg. At 1000 K,
what would be the rms speed of these H2 molecules?**

**a. less than 1 m/s**

**b. 3.5 x 103 m/s**

**c. 1.2 x 107 m/s**

**d. more than 109 m/s**

**e. none of these**

In: Physics

A woman is listening to her radio, which is 176 m from the radio station transmitter.

(a)

How many wavelengths of the radio waves are there between the transmitter and radio receiver if the woman is listening to an AM radio station broadcasting at 1180 kHz?

wavelengths

(b)

How many wavelengths are there between the transmitter and radio if she changes to an FM station broadcasting at 96.9 MHz?

wavelengths

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A photon collides with an electron, and is scattered in a direction 60.0∘60.0∘ from its original direction. If the photon loses 60.060.0% of its momentum in the process, what was the photon's initial wavelength?

In: Physics

A) Given that the blood flow through the body is 5 liters to minute, estimate the number of capillaries there are in the body using the following. Assume the diameter each capillary is 10 micrometers and the speed of blood through them is 0.03 cm/s

B) During a ventricle contraction, the average pressure pushing blood into the aorta is 100 mmHg. What is this pressure in Pascals? (use the density of mercury at 14 g/ml and the acceleration due to gravity of 10 m/s^2)

C) During a contraction, the heart pumps 75 ml of blood into the Aorta. Given the pressure above, how much work is done (in Joules) on the blood by the heart during a contraction?

D) Assuming a heart rate of 60 beats per minute, how many Calories (kilocalories) are burned just circulating blood during a day. (Take the approximation of 4 Joules per calorie.)

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Aside from a higher standard deviation, how does the weighted average lambda value for CuK employed when it comes to XRAY Diffraction provide a more accurate answer?

In: Physics

Michael Faraday unsuccessfully attempted to measure the
potential difference across the River Thames due to the flow of
water (which is a good conductor due to dissolved salts) in the
earth's field. At Waterloo Bridge, where Faraday made his attempt,
the river is 200 m wide and flows eastward at 2.4m/s . The earth's
magnetic field here has a magnitude of 50 *?*T and is tipped
65?from the horizontal, so it has both horizontal (north) and
vertical (down) components.

**Part B**

What is the magnitude of the potential difference?

In: Physics

Make the curvature radius 0.6 , the refractive index 1.5, and the
diameter 0.6 . Place the lamp so that the source of light is
120 from the middle of the lens (use the ruler).

The focal length of the lens is ____________, and the focal plane
is ___________ from the lens.

120 cm / 120 cm

60 cm / 120 cm

60 cm / 60 cm

30 cm / 120 cm

60 cm / 180 cm

SubmitHintsMy AnswersGive UpReview Part

Correct

For this lens, when the object is 120 cm away, the image is the
same distance on the other side of the lens.

Part H

Now, move the lamp so that it is 90 from the center of
the lens.

How far from the lens is the image?

60 cm

90 cm

180 cm

120 cm

160 cm

In: Physics

A 0.49-kg cord is stretched between two supports,7.3m apart. When one support is struck by a hammer, a transverse wave travels down the cord and reaches the other support in 0.83s .

What is the tension in the cord? **(**Express your answer to two significant figures and include the appropriate units.

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A beaker is sitting on a scale. Block A in the figure hangs by a cord from spring balance D and is submerged in a liquid C contained in beaker B. The mass of the beaker is 1.35kg; the mass of the liquid is 1.70kg. Balance D reads 3.55kg and balance E reads 7.50kg. The volume of block A is 3.90×10-3 m^3.

What is the density of the liquid?

p=? kg/m^3

What will the balance D read if block A is pulled up out of the liquid?

Mass D=? kg

What will the balance E read if block A is pulled up out of the liquid?

Mass E=? kg

What is the density of the liquid?

p=? kg/m^3

What will the balance D read if block A is pulled up out of the liquid?

Mass D=? kg

What will the balance E read if block A is pulled up out of the liquid?

Mass E=? kg

In: Physics

You are investigating the report of a UFO landing in an isolated portion of New Mexico, and encounter a strange object that is radiating sound waves uniformly in all directions. Assume that the sound comes from a point source and that you can ignore reflections. You are slowly walking toward the source. When you are 7.5 m from it, you measure its intensity to be 0.11W/m2.

An intensity of 1.0W/m2 is often used as the "threshold of pain". How much closer to the source can you move before the sound intensity reaches this threshold?

In: Physics