Two train whistles have identical frequencies of 220 Hz. When one train is at rest in the station sounding its whistle, a beat frequency of 10.0 Hz is heard from the other train that is approaching the station. What is the speed of the approaching train? Assume that the speed of sound is 340 m/s.

Speed of the approaching train = 15.45 m/s

Explanation:

Given:

Frequency F0 = 220 Hz

Beat frequency F1 = 10.0 Hz

Find:

Speed of the approaching train

Computation:

Approaching frequency F2 = 220 + 10.0 Hz

Approaching frequency F2 = 230 Hz

Doppler shift;

F = [(v+v0)/(v-vS)]F0

230 = [(340+v0)/(340-0)]220

V0 = 15.45 m/s

Speed of the approaching train = 15.45 m/s

  1.the balanced   chemical equation is as below

cu +   2 ag(no)₃ → cu(no₃)₂   +2 ag

2.the   much silver   produced   is   50.9 g

step 1: find the   moles of cu

moles =   mass÷   molar mass

  from periodic table the molar mass of cu = 63.5 g/mol

moles is therefore = 15.00 g÷ 63.5 g/mol = 0.236   moles

step 2: use the mole ratio to determine the   moles of ag

from equation above   cu: ag   is 1: 2

therefore the moles of ag   =0.236   moles   x 2/1 =0.472   moles

step 3: find the mass   of ag

mass = moles x molar mass

from periodic table   the molar mass of ag =107.87 g/mol

mass   = 0.472   moles x 107.87 g/mol = 50.9 g

3.   the   much   silver   collected worth is   1.797 oz

  convert   50.9 g   to oz

that is   1 gram = 0.0353 oz

          50.9 grams =?   oz

by cross multiplication

={(50.9 grams x 0.0353 oz) / 1   gram}   =1.797 oz

where are the vectors ?