Newton's Law of Universal Gravitation Problem 1 : Substitute the known values 8 Earth = 9. 81 meters/ sec - and -Earth = 637 1 km to determine the

I need help with numbers 1 and 2 please! I don't understand how to do the calculations.

Newton's Law of Universal GravitationProblem 1 : Substitute the known values 8 Earth = 9. 81 meters/ sec - and -Earth = 637 1 kmto determine the mass of the Earth .F = maM`Problem 2: Is your answer to Problem I reasonable ? That's hard to say off- hand : mostof us are not accustomed to such huge masses , so we have no way ofsaying whether our estimate is in the right ballpark or not . One way oftesting your value for the Earth's mass is to compute what value it impliesfor the Earth's density . Recall that density is mass divided by volume , andthat the volume of a sphere of radius r is- DEV 3*So , use your answer to Problem I to compute the density of the Earth( more precisely , the average density of the Earth ) . How does your answercompare to what you know from chemistry about the typical densities ofsolid objects ? ( Please note that you will obtain the Earth's density inkilograms per cubic meter . You may want to convert this to grams percubic centimeter , which is the unit of density most commonly used inchemistry . A chart of the densities of solid objects may be found online . )Problem 3 : Suppose that an object is dropped , not from the Earth's surface , but from aHeight /Earth above the Earth's surface . With what acceleration will it start121