Aball was kicked horizontally off a clif at 15m/s, how high was the cliff if the ball landed 83 m from base of the cliff

The ball's horizontal position at time is

The ball has initial velocity in the horizontal direction only, so . Then the time it takes for the ball to travel 83 m horizontally is given by

Meanwhile, the ball's vertical position at time , starting at the height of the cliff , is given by

where is the acceleration due to gravity. After 5.5 seconds, the ball hits the ground, so that when , and we use this to solve for :

u=13

v=30

s/t=u+1\2at

=13+431/2

=13+265.5

=278.5

  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