Acluster of galaxies has a radius of about 4.8 million light-years (4.5×1022 m ) and an intracluster medium with a temperature of 6.0×107 k . [hint: consult mathematical insight 23.3.]
1) estimate the mass of the cluster. give your answer in both kilograms and solar masses. suppose the combined luminosity of all the stars in the cluster is 7.5×1012 lsun .
express your answer using two significant figures.
m=
2) express your answer using two significant figures.
m=
3) what is the cluster's mass-to-light ratio?
express your answer using two significant figures.

A. they hold atoms  together with a molecule.its a force that exist between molecules. hope this .

Answertraveling around a circular trackexplanation"traveling around a circular track" is the best answer as you could be traveling around a circular track at a constant speed. your velocity would therefore have the same magnitude but will always be constantly direction. since acceleration is the rate of change of velocity, the rate of change will only involve the direction of velocity and not the magnitude.wrong choices: "an object at rest" does not accelerate at all"increasing speed while traveling around a curve" means that the acceleration will not be constant due to only change in direction; it will be constant due to both magnitude and direction"an object in free fall" does not necessarily change direction