The power required to exert 4-n force over 3 meters in 2 seconds is

a) 4 w.
b) 6 w.
c) 8 w.
d) 12 w.
e) none of the above

B) 6 W

Explanation:

First of all, we need to find the work done by the force. This is given by

where

F = 4 N is the magnitude of the force

d = 3 m is the distance through which the force is applied

Substituting,

Now we can find the power, which is given by

where

W = 12 J is the work done by the force

t = 2 s is the time taken

Substituting,

  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

fgravity=10x10=100n case 1

fgravity=30x20=600n case 2

6 times more