A wavelength approaching land at 25 m/s is 4.0 x 102 m. What is its period?

16 s

Explanation:

The frequency of a wave is the number of oscillations of the wave per second. It is given by:

where

v is the wave speed

is the wavelength

For the wave in this problem we have

v = 25 m/s

So the frequency is

The period of a wave is the time taken for one complete oscillation, and it is equal to the reciprocal of the frequency:

So the period of this wave is:

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂