A man travels a certain distance by train in 4 hours and 12 minutes at the speed of 44.8 km per hour. How much time will it take to cover the same distance, if the speed of the train is increased to 58.8 km per hour?​

Explanation:

12 minutes is 1/5 or 0.2 of an hour

distance traveled in 4.2 hrs. is

d = vt = 44.8(4.2) = 188.16 km

at the higher speed, the trip will take'

t = d/v = 188.16/58.8 = 3.2 hrs or 3 hrs and 12 minutes

  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

-first use of geothermal energy occurred more than 10,000 years ago in north america by american paleo-indians

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hope this