Aboy of mass 60 kg runs up a staircase of 50 steps in 10s. if height of each steps is 12 cm, find the power

350 W

Explanation:

50 steps × 0.12 m/step = 6 m

Power = work / time

P = mgh / t

P = (60 kg) (9.8 m/s²) (6 m) / 10 s

P = 352.8 W

Rounding to two significant figures, the power is 350 W.

a. is the answer because they are not shared

  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