Three individuals stand with all of their weight on the heel of one foot: a man of weight 600 N and a heel area of 100 cm2, a child of weight 200 N and a heel area of 25 cm2 and woman of weight 450 N and a heel area of 2 cm2. The one exerting the least pressure on the ground is .

The man of weight 600 N with a heel area of 100 cm2

Explanation:

Pressure is defined as force per unit area. Therefore

Pressure (P) = Force(F)/Area (A)

For the man, P = 600/0.01 = 60,000 Pa

For the child, P = 200/0.0025 = 80,000 Pa

For the woman, P = 450/0.0002 = 2,250,000 Pa

Hence, the one exerting the least pressure on the ground is the man with 60,000 Pa of pressure.

  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

no sign of dia of fuel cell