Neil studied how a pulley helps move an object. Neil tied a rope to an object with a mass of 10 kilograms (kg) and attached it to a pulley. He then pulled down on the rope.

When Neil pulled down on the rope, which did he most likely learn about the force required to lift the object?

It was half of the weight of the object.

It was equal to the weight of the object

It was two times the weight of the object.

It was three times the weight of the object.

  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

ice to water 1 water to vapour 2 latent heat

i think the answer is a and b

i wish you luck