The theory of nuclear astrophysics is that all the heavy elements like uranium are formed in the interior of massive stars. These stars eventually explode, releasing these elements into space. If we assume that at the time of the explosion there were
equal amount of U-235 and U-238, how long ago did the star(s) explode that released the elements that formed our Earth? The present U-235/U-238 ratio is 0.007 0 . [The half-lives of U-235 and U-238 are 0.7 × 10^9 yr and 4.47 × 10^9 yr.]
5.9 billion years
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__________is a graph of orbital velocity versus radius in the disk of a galaxy
A) A rotation curve B) A normal distribution C) The H-R diagram D) The light curve
What is meant by spectral resolution?
A) It is a measure of how much energy an object emits in different parts of the electromagnetic spectrum. B) It is a measure of how close two spectral lines can be and still be distinguishable. C) It is a measure of how close two stars can be in the sky and still be distinguishable. D) It is the same as angular resolution but applied to telescopes operating at different wavelengths.
Simple Harmonic Motion: The position of an object that is oscillating on an ideal spring is given by x = (17.4 cm) cos[(5.46 s-1)t]. Write an expression for the velocity of the particle as a function of time using the sine function.
What will be an ideal response?
One bar of atmosphere is roughly equal to Earth's atmospheric pressure at sea level
Indicate whether the statement is true or false