What is the importance of the IPK? What might happen if it did not exist?

See detailed explanation.

Explanation:

Hello,

In this case, since the International Prototype of the Kilogram (IPK) is an object  made of a platinum-iridium alloy that was used to define the magnitude of the mass of the kilogram as it weights 2.2 pounds or approximately 1 kg, yet it was replaced by a new definition of the kilogram based on physical constants. In such a way, it is important because it was the base for the current understanding of what a kilogram is and its relationship with other mass measurements.

Thus, if would not have existed, we were not be able to design and use balances or mass-measuring equipment in order to provide a reliable measure of the real mass of an object.

Best regards.

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.