Water has a density of 1.0 g/cm3 a plastic box has a volume of 78 cm and weighs 80 grams will the box sink or float on water If possible explain thx!

What we'll do:

A method to find whether an object will float or sink in a liquid is to find it's specific gravity with respect to the liquid, The Specific Gravity tells us the percentage of object's mass which will be submerged in water

Finding the Specific Gravity:

Density of Box:

Density = Mass / Volume

Density = 80 grams / 78 cm³

Density = 1.02 grams/cm³

Specific Gravity of Box with respect to water:

Specific Gravity = Density of Box / Density of Water

we know that density of water is 1 gm/cm³, plugging the values

Specific Gravity = 1.02 / 1

Specific Gravity = 1.02

Hence, 102% of the object will be under water

Q. but I've only heard about 100% of something, how can something be more than 100%?

A. The answer is that the extra 2% over the 100% is providing to the object being even deeper underwater

2. angles qrt and qst both measures 156 degrees.

step-by-step explanation:  

we have been given a diagram of a circle and we are told that measure of arc qvt is 156 degrees.  

we can see from our given diagram that angle qrt and angle qst subtends to arc qvt.

since we know that angles subtended by the same arc at the circumference are always equal.

by angle subtended by same arc theorem, measure of angle qrt and angle qst will be equal to the measure of arc qvt.

therefore, angles qrt and qst both measures 156 degrees and 2nd statement is the correct choice.