My cousin proposed this lab that requires me to create a pen and uses its springs to dispense a piece of paper that lay flat on a high surface to the ground. The pen looks like this: From this lab objective, I need to find the K constant of the spring inside the pen using Hooke's law F= -Kx. I was able to find the distance, time, and acceleration (d=1/2at^2) but still unable to figure out how to find the mass to complete my finding in applied force. This image is the only hint he's willing to give me, please help me find the mass or force of this experience?

cousin proposed this lab that requires me to create a pen and uses its springs to dispense a piece of paper that lay flat on a high surface to the ground. The pen looks like this:

From this lab objective, I need to find the K constant of the spring inside the pen using Hooke's law F= -Kx. I was able to find the distance, time, and acceleration (d=1/2at^2) but still unable to figure out how to find the mass to complete my finding in applied force.

  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