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4 years ago

5

You discover a binary star system in which one member is a 15 solar mass main-sequence star and the other star is a 10 solar mas

s giant star. Why should you be surprised, at least at first

1 answer:

Sever21 [200]4 years ago

4 0

Answer:

A star with 15 solar masses is too big to be a main-sequence star.

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A mass weighing 11 lb stretches a spring 4in. The mass is pulled down an additional 3 in and is then set in motion with an initi

Shtirlitz [24]

Answer:

a) $x(t) = 2.845\cdot \cos \left(1.732\cdot t -0.473\pi \right)$ , b) $T = 3.628\,s$ , $A = 2.845\,ft$ , $\phi = -0.473\pi$

Explanation:

a) The system mass-spring is well described by the following equation of equilibrium:

$\Sigma F = k\cdot x - m\cdot g = m\cdot a$

After some handling in physical and mathematical definition, the following non-homogeneous second-order linear differential equation:

$\frac{d^{2}x}{dt^{2}}+\frac{k}{m}\cdot x = g$

The solution of this equation is:

$x (t) = A\cdot \cos \left(\sqrt{\frac{k}{m} } \cdot t + \phi\right)$

The velocity function is:

$v(t) = \sqrt{\frac{k}{m} }\cdot A\cdot \sin \left(\sqrt{\frac{k}{m} }\cdot t +\phi \right)$

Initial conditions are:

$x(0\,s) = 0.25\,ft, v(0\,s) = -5\,\frac{ft}{s}$

Equations at $t = 0\,s$ are:

$0.25\,ft = A\cdot \cos \phi\\-5\,\frac{ft}{s} =\sqrt{\frac{k}{m} }\cdot A\cdot \sin \phi$

The spring constant is:

$k = \frac{11\,lbf}{0.333\,ft}$

$k = 33\,\frac{lbf}{ft}$

After some algebraic handling, amplitude and phase angle are found:

$\phi = -0.473\pi$

$A = 2.845\,ft$

The position can be described by this function:

$x(t) = 2.845\cdot \cos \left(1.732\cdot t -0.473\pi \right)$

b) The period of the motion is:

$T = \frac{2\pi}{\sqrt{\frac{k}{m} } }$

$T = 3.628\,s$

The amplitude is:

$A = 2.845\,ft$

The phase of the motion is:

$\phi = -0.473\pi$

8 0

4 years ago

In principle, when you fire a rifle, the recoil should push you backward. How big a push will it give? Let’s find out by doing a

mixer [17]

Answer:

0.07142 m/s in the opposite direction of the bullet

Explanation:

$m_1$ = Mass of rifle = 70 kg

$m_2$ = Mass of bullet = 0.01 kg

$v_1$ = Velocity of rifle

$v_2$ = Velocity of bullet = 500 m/s

As the momentum of the system is conserved

$m_1v_1+m_2v_2=0\\\Rightarrow v_1=-\frac{m_2v_2}{m_1}\\\Rightarrow v_1=-\frac{0.01\times 500}{70}\\\Rightarrow v_1=-0.07142\ m/s$

The recoil velocity of the rifle is -0.07142 m/s

The negative sign shows the opposite direction of the rifle.

3 0

3 years ago

Hydrogen sulfide, H2S, and hydrogen chloride, HCl, are both gases at temperatures above –50 °C.

vladimir1956 [14]

Explanation:

A gas at higher temperature is able to gain more heat from the environment/surroundings and has more kinetic energy to diffuse at a faster rate.

Hence a temperature at -20°C is more ideal.

Molar mass of H2S = 34.07g/mol

Molar mass of HCl = 36.45g/mol

Since H2S has a smaller molar mass, the same number of moles of H2S gas will diffuse faster as compared to the same number of moles of HCl gas.

Hence the answer is Hydrogen sulfide at -20°C. (D)

5 0

3 years ago

An experiment in which alpha particles were used to bombard thin sheets of gold foil led to the conclusion that an atom is compo

fiasKO [112]

Answer:

a small dense nucleus with positive charge and the nucleus is surrounding by orbiting electrons.

Explanation:

An experiment in which alpha particles were used to bombard thin sheets of gold foil led to the conclusion that an atom is composed mostly of a small dense nucleus with positive charge and the nucleus is surrounding by orbiting electrons.

8 0

3 years ago

After inspecting all of 55,000 kg of meat stored at the Wurst Sausage Company, it was found that 45,000 kg of the meat was spoil

Helen [10]

Answer:

B. Parameter.

Explanation:

After inspecting all of 55,000 kg of meat stored at the Wurst Sausage Company, it was found that 45,000 kg of the meat was spoiled.

The data above is described as a parameter because the data describes the entire population (the meat). the difference between statistic and parameters are statistic is used to describe a sample whereas parameter is used to describe the population.

8 0

3 years ago