• Spanish Help based on his answer, write the missing words to complete the questions that the person on the phone ask?

    Pregunta: ?____________ usted este semestre? Miguel: Tomo cinco clases este semestre.
    Pregunta: ?____________ usted este semestre? Miguel: Tomo cinco clases este semestre.
    2 answers · Languages · 2 months ago
  • Consider a spherical volume of space that is large enough to be considered homogeneous.?

    Select all that apply. Consider a spherical volume of space that is large enough to be considered homogeneous. Also consider a particle on the surface of this volume that is moving away from the center with the Hubble flow. Assuming that the pressure within the volume is negligible, the universe will re-collapse if the particle's Hubble speed... show more
    Select all that apply. Consider a spherical volume of space that is large enough to be considered homogeneous. Also consider a particle on the surface of this volume that is moving away from the center with the Hubble flow. Assuming that the pressure within the volume is negligible, the universe will re-collapse if the particle's Hubble speed is: A. Greater than its escape speed from the mass within the volume B. The same as its escape speed from the mass within the volume C. Less than its escape speed from the mass within the volume
    1 answer · Physics · 1 year ago
  • Has been shown to account for a non-negligible amount - but certainly not all or even most - of the Milky Way's dark matter:?

    Has been shown to account for a non-negligible amount - but certainly not all or even most - of the Milky Way's dark matter: A. Black hole MACHOs B. Neutron star MACHOs C. White dwarf MACHOs D. Red dwarf MACHOs E. Brown dwarf MACHOs F. WIMPs
    Has been shown to account for a non-negligible amount - but certainly not all or even most - of the Milky Way's dark matter: A. Black hole MACHOs B. Neutron star MACHOs C. White dwarf MACHOs D. Red dwarf MACHOs E. Brown dwarf MACHOs F. WIMPs
    2 answers · Astronomy & Space · 1 year ago
  • A star in a globular cluster is observed to pulsate with a period of 15 hours.?

    A star in a globular cluster is observed to pulsate with a period of 15 hours. The star is 200 times fainter than a solar-mass star 100 pc away in the disk of the Milky Way. Calculate the distance to the globular cluster. A. 1 pc B. 50 pc C. 200 pc D. 1 kpc E. 10 kpc F. 30 kpc G. 100 kpc H. 1 Mpc
    A star in a globular cluster is observed to pulsate with a period of 15 hours. The star is 200 times fainter than a solar-mass star 100 pc away in the disk of the Milky Way. Calculate the distance to the globular cluster. A. 1 pc B. 50 pc C. 200 pc D. 1 kpc E. 10 kpc F. 30 kpc G. 100 kpc H. 1 Mpc
    Astronomy & Space · 1 year ago
  • A massive object can approach but never attain the speed of light, because:?

    A massive object can approach but never attain the speed of light, because: A. It would stop moving through time B. It's length would contract to nothing C. It's mass would become infinite D. It would require an infinite amount of energy
    A massive object can approach but never attain the speed of light, because: A. It would stop moving through time B. It's length would contract to nothing C. It's mass would become infinite D. It would require an infinite amount of energy
    4 answers · Physics · 1 year ago
  • Superman is 6.5 feet tall. He is currently flying headfirst with a ground-speed of 0.90 × c. How tall is Superman to observers on the ground?

    Superman is 6.5 feet tall. He is currently flying headfirst with a ground-speed of 0.90 × c. How tall is Superman to observers on the ground? A. 1.2 ft B. 2.1 ft C. 2.8 ft D. 6.5 ft E. 15 ft
    Superman is 6.5 feet tall. He is currently flying headfirst with a ground-speed of 0.90 × c. How tall is Superman to observers on the ground? A. 1.2 ft B. 2.1 ft C. 2.8 ft D. 6.5 ft E. 15 ft
    1 answer · Mathematics · 1 year ago
  • When high-energy cosmic rays strike Earth's atmosphere, they create muons.?

    When high-energy cosmic rays strike Earth's atmosphere, they create muons. Muons are subatomic particles that quickly decay into electrons. When created with low energies and low speeds in laboratories, they decay with a half-life of 2 × 10-6 seconds. However, atmospheric muons are created with high energies and high speeds, typically 0.996 × c.... show more
    When high-energy cosmic rays strike Earth's atmosphere, they create muons. Muons are subatomic particles that quickly decay into electrons. When created with low energies and low speeds in laboratories, they decay with a half-life of 2 × 10-6 seconds. However, atmospheric muons are created with high energies and high speeds, typically 0.996 × c. A scientist with a muon detector in a plane will find that half of the muons travel how far before decaying into electrons? A. 0.05 km B. 0.6 km C. 7 km D. 9 km E. 70 km F. 600 km G. 7,000 km
    1 answer · Physics · 1 year ago
  • A millisecond pulsar has a radius of 10 km and a period of 2 ms. How fast does it rotate at its equator?

    A millisecond pulsar has a radius of 10 km and a period of 2 ms. How fast does it rotate at its equator? (Hint: circumference = 2 × pi × radius, where pi = 3.14) A. 10^-7 × c B. 10^-4 × c C. 0.1 × c D. 0.2 × c
    A millisecond pulsar has a radius of 10 km and a period of 2 ms. How fast does it rotate at its equator? (Hint: circumference = 2 × pi × radius, where pi = 3.14) A. 10^-7 × c B. 10^-4 × c C. 0.1 × c D. 0.2 × c
    2 answers · Physics · 1 year ago
  • X-ray bursters are to neutrons stars as:?

    X-ray bursters are to neutrons stars as: A. Planetary nebulae are to white dwarfs B. Novae are to white dwarfs C. Type Ia supernovae are to white dwarfs D. Type II supernovae are to neutron stars
    X-ray bursters are to neutrons stars as: A. Planetary nebulae are to white dwarfs B. Novae are to white dwarfs C. Type Ia supernovae are to white dwarfs D. Type II supernovae are to neutron stars
    3 answers · Astronomy & Space · 1 year ago
  • Select all that apply. Not all supernova remnants contain a pulsar, because:?

    Select all that apply. Not all supernova remnants contain a pulsar, because: A. There might be a neutron star in the remnant, but it might not be pulsing in Earth's direction. B. There might be a pulsar, but outside of the remnant, if the supernova was asymmetric and imparted the neutron star with a large kick velocity. C. If the supernova was... show more
    Select all that apply. Not all supernova remnants contain a pulsar, because: A. There might be a neutron star in the remnant, but it might not be pulsing in Earth's direction. B. There might be a pulsar, but outside of the remnant, if the supernova was asymmetric and imparted the neutron star with a large kick velocity. C. If the supernova was Type Ia, there would be no neutron star. D. If the supernova was Type II, there would be no neutron star.
    2 answers · Astronomy & Space · 1 year ago
  • Select all that apply. After the sun leaves the main sequence, its helium core will contract until electron degeneracy pressure sets in.?

    Select all that apply. After the sun leaves the main sequence, its helium core will contract until electron degeneracy pressure sets in. Consequently, when helium burning begins: A. The core will expand like a gas, causing the core density to decrease. This will cause the helium burn rate to slow to a steady value. B. The core will behave like a... show more
    Select all that apply. After the sun leaves the main sequence, its helium core will contract until electron degeneracy pressure sets in. Consequently, when helium burning begins: A. The core will expand like a gas, causing the core density to decrease. This will cause the helium burn rate to slow to a steady value. B. The core will behave like a liquid and not expand. Consequently, the core will grow hotter, causing the helium burn rate to increase, causing the core to grow hotter, etc. C. Electron degeneracy pressure will be maintained until the core grows hot enough for it to behave like a gas again.
    1 answer · Astronomy & Space · 1 year ago
  • Which of the following statements is not true?

    Which of the following statements is not true? A. Dust in dark clouds scatters visible light, making them opaque at visible wavelengths. B. Since dust does not scatter light at sufficiently longer infrared wavelengths, dark clouds are transparent at these wavelengths. C. Atomic hydrogen and a variety of molecules in dark clouds emit radio light,... show more
    Which of the following statements is not true? A. Dust in dark clouds scatters visible light, making them opaque at visible wavelengths. B. Since dust does not scatter light at sufficiently longer infrared wavelengths, dark clouds are transparent at these wavelengths. C. Atomic hydrogen and a variety of molecules in dark clouds emit radio light, making them bright at radio wavelengths. D. Dark clouds that are not collapsing are supported against collapse by a combination of thermal pressure, rotation, and magnetic fields. E. Dark clouds that are collapsing ultimately form a single system, most likely either a single star or a binary star system.
    1 answer · Astronomy & Space · 1 year ago
  • Planetary nebulae are the end result of:?

    Planetary nebulae are the end result of: A. Increasingly unstable planets B. Hydrogen-shell flashes that make <8-solar-mass red giants increasingly unstable C. Hydrogen-shell flashes that make >8-solar-mass red giants increasingly unstable D. Helium-shell flashes that make <8-solar-mass red giants increasingly unstable E. Helium-shell... show more
    Planetary nebulae are the end result of: A. Increasingly unstable planets B. Hydrogen-shell flashes that make <8-solar-mass red giants increasingly unstable C. Hydrogen-shell flashes that make >8-solar-mass red giants increasingly unstable D. Helium-shell flashes that make <8-solar-mass red giants increasingly unstable E. Helium-shell flashes that make >8-solar-mass red giants increasingly unstable
    2 answers · Astronomy & Space · 1 year ago
  • A solar-mass star's motion up the subgiant & red-giant branches is similar to its motion up the asymptotic giant branch in that:?

    Select all that apply. A solar-mass star's motion up the subgiant and red-giant branches is similar to its motion up the asymptotic giant branch in that: A. The core (helium and carbon, respectively) is not burning and consequently contracts. B. The core heats the burning shell around it (hydrogen and helium, respectively), which increases its... show more
    Select all that apply. A solar-mass star's motion up the subgiant and red-giant branches is similar to its motion up the asymptotic giant branch in that: A. The core (helium and carbon, respectively) is not burning and consequently contracts. B. The core heats the burning shell around it (hydrogen and helium, respectively), which increases its burn rate and consequently causes the outer layers to expand and cool. C. The core eventually contracts to the point that electron degeneracy pressure sets in.
    1 answer · Astronomy & Space · 1 year ago
  • Which of the following does not occur with the others?

    Which of the following does not occur with the others? A. Dark clouds B. High-mass stars C. Emission nebulae D. Reflection nebulae E. Planetary nebulae
    Which of the following does not occur with the others? A. Dark clouds B. High-mass stars C. Emission nebulae D. Reflection nebulae E. Planetary nebulae
    1 answer · Astronomy & Space · 1 year ago
  • A contact binary star system consists of:?

    A contact binary star system consists of: A. Two stars that do not fill their Roche lobes B. A giant star that fills its Roche lobe and transfers mass to the other star C. Two giant stars that fill their Roche lobes, creating a common envelope D. A giant star that fills it Roche lobe and transfers mass to a white dwarf E. A giant star that... show more
    A contact binary star system consists of: A. Two stars that do not fill their Roche lobes B. A giant star that fills its Roche lobe and transfers mass to the other star C. Two giant stars that fill their Roche lobes, creating a common envelope D. A giant star that fills it Roche lobe and transfers mass to a white dwarf E. A giant star that fills it Roche lobe and transfers mass to a neutron star F. A giant star that fills it Roche lobe and transfers mass to a black hole
    1 answer · Astronomy & Space · 1 year ago
  • A protostar's radius decreases by a factor of 100, its surface temperature increases by a factor of two before it bc a main sequence star.?

    A protostar's radius decreases by a factor of 100 and its surface temperature increases by a factor of two before it becomes a main sequence star. It's luminosity: A. Decreases by a factor of 160,000 B. Decreases by a factor of 625 C. Decreases by a factor of 40 D. Increases by a factor of 40 E. Increases by a factor of 625 F. Increases... show more
    A protostar's radius decreases by a factor of 100 and its surface temperature increases by a factor of two before it becomes a main sequence star. It's luminosity: A. Decreases by a factor of 160,000 B. Decreases by a factor of 625 C. Decreases by a factor of 40 D. Increases by a factor of 40 E. Increases by a factor of 625 F. Increases by a factor of 160,000
    1 answer · Astronomy & Space · 1 year ago