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Now use this equation set to answer the questions in the following 
example.
Step 4:
View the five equations in the Projectile Motion  set. All five are 
used interchangeably in order to solve for missing variables (see 
the next example).
#EQN#  #NXEQ#  #NXEQ#  #NXEQ#  #NXEQ#
Step 5: Examine the variables used by the equation set.
#VARS#
and —as ˜ needed
Example:
You estimate that on average professional goalkeepers can 
punt a soccer ball a distance (R) of 65 meters downfield at an 
elevation angle (
0
) of 50 degrees. At what velocity (v
0
) do they 
kick it
? How high is the ball halfway through its flight? How far 
could they drop kick the ball if they used the same kicking 
velocity, but changed the elevation angle to 30 degrees? 
(Ignore the effects of drag on the ball.)
Step 1: Start solving the problem.
#SOLV#
Step 2:
Enter the known values and press the soft menu key 
corresponding to the variable. (You can assume that x
0
 and y
0
are zero.) Notice that the menu labels turn black as you store 
values. (You will need to press 
L to see the variables that are 
initially shown.)
SG49A.book  Page 2  Friday, September 16, 2005  1:31 PM