2.5

Calculate the escape velocity from a neutron star. Here's what to do: 1. Look up the mass of the Sun in kilograms (one 'solar mass'). 2. Assume the mass of the neutron star is two solar masses, M = 2 x (answer from 1). 3. Assume the radius of the Neutron Star is 10,000 meters (= R). 4. With these units, use G = 6.67 x 10-11 . 5. Calculate the escape velocity in m/s by plugging the above numbers into the formula vesc = square root of 2 G M divided by R end root 77,000,000 m/s 154,000,000 m/s 231,000,000 m/s 462,000,000 m/s

231,000,000 m/s

Calculate the Schwarzschild radius for the Sun. Here's what to do: 1. Use M = 1 solar mass = ______ kg, use the number you looked up in the previous problem. 2. To get an answer in meters, use G = 6.67 x 10-11 and c = 300,000,000 . 3. Plug the numbers into the formula RS = 2 G M / c2 . 2964 m 29,644 m 296,444 m 296,444,444 m

2964 m

Gravitational waves Are how pulsars pulse. Carry material into black holes. Are traveling distortions of space and time. Do not carry energy.

Are traveling distortions of space and time.

From which of the following will a wave of light show the greatest gravitational redshift: a white dwarf a giant planet like Jupiter Earth the sun

a white dwarf

When a light wave leaves a region of strong gravity, compared to the same wave leaving a spaceship in empty space, the wave in strong gravity will have a longer wavelength a lower frequency less energy a gravitational redshift all of the above

all of the above

When Einstein proposed his General Theory of Relativity, he suggested some pretty strange ideas about space, time, and gravity. How did scientists in 1919 show that Einstein's theory described the behavior of the real world and wasn't just a crazy hypothesis? by finding x-rays from a black hole by using an H-R diagram for a nearby cluster of stars by discovering the process of nuclear fusion by dropping different weights from very tall buildings by observing starlight coming close to the Sun during an eclipse

by observing starlight coming close to the Sun during an eclipse

According to Einstein's general theory of relativity, the stronger a star's gravity, the weaker its pull on another star will be the slower time runs near it the weaker the x-rays we see from it the smaller the event horizon will be of the black hole it makes the less space-time around it will be distorted

the slower time runs near it