-Need some physics help-

MacBaine

Banned
Aug 23, 2001
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Ok, I am writing a lab report for an experiment on projectile motion. Basically, we shot a bunch of water balloons, measured the distance, angle of fire, and time. Out of this, we are expected to extract initial X velocity, initial Y velocity, and initial velocity. Then, we must find the theoretical time and distance. HOWEVER, I don't believe that I can accurately find the theoretical values, because to do so, she expects us to use the calculated velocities, but those are based off of the measured time!

Basically, we are given the measured time, angle, and distance... and we are supposed to find the theoretical distance and time. Wouldn't that basically mean finding the time and distance based solely on the angle? Maybe I am just missing something...help me out! :confused:
 

NewSc2

Diamond Member
Apr 21, 2002
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Originally posted by: MacBaine
Ok, I am writing a lab report for an experiment on projectile motion. Basically, we shot a bunch of water balloons, measured the distance, angle of fire, and time. Out of this, we are expected to extract initial X velocity, initial Y velocity, and initial velocity. Then, we must find the theoretical time and distance. HOWEVER, I don't believe that I can accurately find the theoretical values, because to do so, she expects us to use the calculated velocities, but those are based off of the measured time!

Basically, we are given the measured time, angle, and distance... and we are supposed to find the theoretical distance and time. Wouldn't that basically mean finding the time and distance based solely on the angle? Maybe I am just missing something...help me out! :confused:

if you used distance it fired and angle, couldn't you calculate the velocity from that?
 

amdskip

Lifer
Jan 6, 2001
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Couldn't you use the real angle and the measured velocity to find the expected distance and then use the real angle and the measured distance to find the velocity.
 

MacBaine

Banned
Aug 23, 2001
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Originally posted by: NewSc2
Originally posted by: MacBaine
Ok, I am writing a lab report for an experiment on projectile motion. Basically, we shot a bunch of water balloons, measured the distance, angle of fire, and time. Out of this, we are expected to extract initial X velocity, initial Y velocity, and initial velocity. Then, we must find the theoretical time and distance. HOWEVER, I don't believe that I can accurately find the theoretical values, because to do so, she expects us to use the calculated velocities, but those are based off of the measured time!

Basically, we are given the measured time, angle, and distance... and we are supposed to find the theoretical distance and time. Wouldn't that basically mean finding the time and distance based solely on the angle? Maybe I am just missing something...help me out! :confused:

if you used distance it fired and angle, couldn't you calculate the velocity from that?

Not without the time.
 

MacBaine

Banned
Aug 23, 2001
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Originally posted by: amdskip
Couldn't you use the real angle and the measured velocity to find the expected distance and then use the real angle and the measured distance to find the velocity.

There was no measured velocity, it had to be calculated using the distance and time.
 

brtspears2

Diamond Member
Nov 16, 2000
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Max range = v intial^2/g(sin 2(theta))

Horizontal motion x-x inital = v inital(time)

vertical motion y- y intial = (v intial*cos theta)time

Or something like that.... dont take my word for it.
 

MacBaine

Banned
Aug 23, 2001
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Originally posted by: brtspears2
Max range = v intial^2/g(sin 2(theta))

Horizontal motion x-x inital = v inital(time)

vertical motion y- y intial = (v intial*cos theta)time

Or something like that.... dont take my word for it.

I don't think you read my post