(adsbygoogle = window.adsbygoogle || []).push({}); Couples of physics questions.....

i have couples of physics question..can someone help..thanks in advance...

1.Synchronous communications satellites are placed in a circular orbit that is 1.57 x 107 m above the surface of the earth. What is the magnitude of the acceleration due to gravity at this distance?

2.At a distance H above the surface of a planet, the true weight of a remote probe is 14.7 percent less than its true weight on the surface. The radius of the planet is R. Find the ratio H/R.

3.While moving in, a new homeowner is pushing a box across the floor at a constant velocity. The coefficient of kinetic friction between the box and the floor is 0.419. The pushing force is directed downward at an angle theta below the horizontal. When theta is greater than a certain value, it is not possible to move the box, no matter how large the pushing force is. Find that value of theta.

for number1 i know i'm suppose to used F=ma and a=GM/R^2 ......but i dunno what's R...so i don't know what to do...

#2..i'm just lost..don't know what to do...

#3..dymanic_Friction_Coeficient * [m*g + F_applied*sin(theta)]=F_applied*cos(theta) ....is this the forumla for it..if it's..i don't know what number goes to which variables...please help...thanks

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# Homework Help: Couples of physics questions .

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