Answer:
Frequency, f = 0.6 Hz
Explanation:
We have,
Number of waves passing through a point are 3
Time for which the waves are passing is 5 seconds
It is required to find the frequency of a wave. The frequency of a wave is defined as the no of waves per unit time. So,

So, the frequency of a wave is 0.6 Hz.
Answer:
Sand
Explanation:
with salt distillation will work, heat the solution and collect the water in a seperate beaker
With sugar you do the same, boil away the water and collect the water vapour, you'll be left with sugar in the original container and water if you collected it
Use a fraction of column and heat the solution, the alcohol will be seperated out
Sand is the only one that uses mechanical filtration
The buoyancy of an object is dictated by its density. So let us calculate for density, where:density = mass / volume
Calculate the volume first of a solid cube:volume = (6 cm)^3 = 216 cm^3 = 216 mL
Therefore density is:density = 270 g / 216 mLdensity = 1.25 g / mL
Therefore this object will float in the layer in which the density is more than 1.25 g / mL.