# Given the following, what is the tension in the string when the nearest mass is a distance of 686 km from the Black hole? #G=6.673×10^-11 m^3kg-1s-2#

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Two masses of 1 kg each are connected by a light, inextensible string of one metre in length. The two masses are now made to approach a Black Hole of mass #8.18×10^30 kg# such that the string connecting them lies along a radius.

Two masses of 1 kg each are connected by a light, inextensible string of one metre in length. The two masses are now made to approach a Black Hole of mass

##### 1 Answer

#### Explanation:

The amount of tension is given by the difference in gravitational force between the two masses. Let A and B be the masses, with A being closer to the black hole O. Then:

As the A and B masses are equal we substitute

Now put in numbers and calculate:

Then