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?

In: Physics

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?

In: Physics

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.

In: Physics

**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

In: Physics

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.)

In: Physics

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

What volume at STP would be required to react with 0.100 mol of hydrogen to produce ammonia?

In: Chemistry

The hydroxide ion has the formula OH−. The solubility-product constants for three generic hydroxides are given here.

Generic hydroxide | Ksp |

XOH | 1.70×10−8 |

Y(OH)2 | 2.70×10−10 |

Z(OH)3 | 8.30×10−15 |

The removal of an ion is sometimes considered to be complete when its concentration drops to 1.00×10−6 M. What concentration of hydroxide would cause Y2+ to "completely" precipitate from a solution?

In: Chemistry

what is the difference between the *Gibbs energy of a
reaction mixture* and the *Standard Gibbs energy of
reaction*.

In: Chemistry

Calculate how to prepare 500 mL of 32.5 part per million KOH from a solution 50% of KOH with a density of 1.58 g/mL

In: Chemistry

The pressure of a monatomic ideal gas doubles during an adiabatic compression. What is the ratio of the final volume to the initial volume (Vf/Vi)?

In: Chemistry