a ball is thrown horizontally off a cliff 18.2 m/s and hits the ground 30.9 m from the base of the
cliff. how high is the clift?

14 m

Explanation:

This situation is related to parabolic motion and can be solved by the following equations:

(1)

(2)

Where:

is the horizontal distance travelled by the ball

is the ball's initial velocity

is the angle (it was thrown horizontally)

is the time

is the ball's final height

is the ball's initial height and the cliff height as well

is the acceleration due gravity

Let's begin by finding from (1):

(3)

(4)

(5)

Isolating from (2):

(6)

Substituting (5) in (6):

(7)

Finally:

  1.the balanced   chemical equation is as below

cu +   2 ag(no)₃ → cu(no₃)₂   +2 ag

2.the   much silver   produced   is   50.9 g

step 1: find the   moles of cu

moles =   mass÷   molar mass

  from periodic table the molar mass of cu = 63.5 g/mol

moles is therefore = 15.00 g÷ 63.5 g/mol = 0.236   moles

step 2: use the mole ratio to determine the   moles of ag

from equation above   cu: ag   is 1: 2

therefore the moles of ag   =0.236   moles   x 2/1 =0.472   moles

step 3: find the mass   of ag

mass = moles x molar mass

from periodic table   the molar mass of ag =107.87 g/mol

mass   = 0.472   moles x 107.87 g/mol = 50.9 g

3.   the   much   silver   collected worth is   1.797 oz

  convert   50.9 g   to oz

that is   1 gram = 0.0353 oz

          50.9 grams =?   oz

by cross multiplication

={(50.9 grams x 0.0353 oz) / 1   gram}   =1.797 oz

d. air pressure decreases as altitude increases.