00:01
All right, so in this problem, let in part a, the acceleration due to gravity of its surface, acceleration due to gravity at surface, this is g0, this is gm over r square.
00:23
And we know the value of g, this is a universal constant, right? this is 10 power minus 11 times 6 .2 times 10 to the power 24 this is mass and the radius is 7 .28 times 10 to the power 6 whole square this is given in the problem right so this is 7 .8 meter per second square so so this is let let let this is less than the acceleration due to gravity of earth right so let in part b the weight of a person this is given by w and this is m g not so this is 80 times 7 .8 this will be 624 newton so this will be the weight of the person now in part c here in part c here we are asked to calculate this are the velocity so we will apply the energy conservation law which is one half mv square plus minus g m sub m over r and this is zero this is the conservation law of energy so from here if we solve power we will be square root 2 g m over r and we know the value so if we put this this will be two times 6 .6 7 times 10 to the power minus 11 times 6 .2 times 10 to the power minus 1 24 and divided by 7 .28 times 10 to the power 6.
02:08
Right? so if we use a calculator and calculate this value, this will be at 10 ,658 .8 meter per second.
02:20
Now in part d here, this is given by gm sub m over r and this will be a 6 .4 .4.
02:34
7 times 10 to the power minus 11 times 6 .2 10 to the power 24 times 80 and divided by 7 .28 times 10 to the power of 6.
02:48
So if you use a calculator, so just calculated with a calculator, this will be 45, 44, 39, 50, 604 jowls, right? to part in part d here.
03:07
So in party d we are asked to calculate the work done right...