Use the work energy theorem to solve each of these problems and neglect air resistance in all cases. a) a branch falls from the top of a 98.0 m tall redwood tree, starting from rest. how fast is it moving when it reaches the ground? b) a volcano ejects a boulder directly upward 545 m into the air. how fast was the boulder moving just as it left the volcano?

a)43.8 m/s

b)103.54 m/s

Explanation:

Work energy theorem

Δ Δ

a) In this part v1=0 and h2=0

=0

b) in this part v2=0, h1= 0, and h2= 545m

answer: question1

1,000 tons

question2

3: 8

question 3

store d

step-by-step explanation:

  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