Astone is tied to a string and whirled around in a circle at
aconstant speed. is the string more likely to break when the
circleis horizontal or when it is vertical? account for your
answer, assuming the constant speed is the same in each case.

Vertical circle.

Explanation:

According to the question:

When the stone tied string moves in horizontal circle, then the tension in the string is provided by the centripetal force.

When the stone tied string moves in a vertical circle, then the tension is provided by the centripetal force as well as its weight.

Thus the probability of breaking in the vertical circle is more.

Refer to the fig shown:

In case of horizontal circle:

The centripetal force for a circle of radius R is given by:

Now, at point P:

Since, T = 0

                             (1)

Now, at point Q:

       (2)

Also, by using the law of conservation of energy, total mechanical energy at point P and Q will be conserved:

Using eqn (1):

                               (3)

Now, using eqn (2) and (3):

Thus tension at point Q is greater than the force at point P.

causes

fossil fuels burn

cities become more industrialized

human population grows worldwide

bacteria that live on the ocean floor are sustained by phytoplankton. phytoplankton, microscopic marine photosynthetic organisms, have a vastly significant role to play not only in the marine food web of which they’re part of, but also on a more global scale. despite their infinitely small size in comparison to other marine organisms, these tiny creatures occupy an immensely important ecological niche: they are the foundation of the marine food web, and as primary producers, play key roles in supporting all other organisms in the marine environment, as well as in the regulation of the earth’s climate through the sequestration of carbon, oxygen production, and other related processes. phytoplankton account for roughly half of all global primary productivity; therefore, their significance extends far beyond the marine environment alone. there is an intriguing sense of irony in the realization that these tiny living beings that often live out their existence unnoticed and undetected by the rest of the world, have such a far-reaching impact on the lives of virtually all other living organisms on the planet, particularly on those in the marine environment. the world that we have become accustomed to has been and is continuously shaped by the workings of these miniscule yet vital “plants of the sea”.

hope this !