From a vantage point very close to the track at a stock car race, you hear the sound emitted by a moving car. you detect a frequency that is 0.86 times as small as the frequency emitted by the car when it is stationary. the speed of sound is 343 m/s. what is the speed of the car?

55.8 m/s

Explanation:

= Actual frequency of sound emitted by car

= frequency observed when the car moves =

= Speed of sound = 343 m/s

= Speed of car

Frequency observed is given as

  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