First read the introduction.
Seconds look at the pictures how to build it.
Answer:
The ball will fly tangential to the original circle
Explanation:
The image here is missing, however we can still answer to the question.
In fact, the circular motion of the ball when it is tied to the rope is a combination of two separate effects:
1- The centripetal force, in the form of the tension in the rop, that pulls the ball at any time towards the centre of the circular path
2- The inertia of the ball, which tends to continue its motion in a straight direction, tangential to the circle and perpendicular to the direction of the centripetal force
When child let the string go, there is no more tension in the string acting on the ball, and therefore, there is no longer a centripetal force.
As a result, number 1) disappears, and therefore there is only the inertia of the ball that will determine its motion: and therefore, the ball will continue its motion straight in a direction tangential to the original circle.
Answer: Lithium
Explanation: The balanced chemical equation is:

It can be seen, 4 moles of lithium combines with 1 mole of oxygen gas to produce 2 moles of lithium oxide.
Thus 8.4 moles of lithium combines with=
of oxygen gas to produce 4.2 moles of lithium oxide.
As, Lithium limits the formation of product, it is the limiting reagent and Oxygen gas is present in excess, it is called the excess reagent. (4.6-2.1)=2.5 moles of oxygen gas are present in excess.
The answer is light years