How to find initial velocity with height, distance and angle

In summary, the task is to find the initial velocity of a water fountain using the given data: height (bottom to apex), distance (from spout to end of stream), time it takes to travel, and the angle the water shoots from. The equations to be used are V=d/t for the horizontal component and vf=vi+at for the vertical component. However, there may be slight variations in the results due to the imperfections in the collected data and the neglect of factors such as wind and drag. Further clarification may be needed on the angle, time, and height measurements to ensure accurate calculations.
  • #1
Jordann2222
1
0

Homework Statement


We need to fin the initial velocity of a water fountain. The data I have collected is:
Height (bottom to apex)= 0.042 m
Distance (from spout to end on the stream)= 0.112 m
Time (it takes to travel)= .25 seconds
Angle the water shoots from= 50 degrees

Here is more if it helps.
Vertical
- D= .042 m
- T= .25 s
- Vfinal= 0 m/s
- a= 9.8 m/s2
- angle= 50 degrees
Horizontal
- D= .112 m
- T= .25 s
- angle= 50 degrees


Homework Equations


V= d/t, This can be used to find the horizontal component ( in the x direction) because Vxcomponent= average velocity.
Vycomponent= vertical initial velocity
vf= vi + at
d=Vi *t +1/2at2
a= acceleration t= time d=distance ( only used with Vertical data)
Vf2= vi2 + 2ad

The Attempt at a Solution


I know that I must find the x and y component vectors but I do not know what equation to use. I tried this four different ways and got four different answers and I'm just really frustrated. I was told to use the vf= vi + at equation for the vertical component and the v=d/t for the horizontal, and they said something about half time, I don't know.
 
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  • #2
One problem is that you have collected more than enough information, creating more than one way to figure it out. Naturally, not all your data will be perfect, and the equations will ignore wind and drag. Consequently, different approaches will yield slightly different answers.
Is the angle to horizontal? I assume so.
Is the .25s the time to reach max height or the time to hit the ground? (What should be the relationship between the two?)
Is ground level the same as spout level? If not, is the .042m the height difference between them, the height from ground to max height of water, or the height from the spout to max height of water?
The datum I would trust least is the time measurement. As a check, if an object is dropped from a height of .042m, how long should it take to hit the ground?
 

1. How do I calculate initial velocity using height, distance, and angle?

The formula for calculating initial velocity using height, distance, and angle is v0 = √(g * h / sin(2θ)), where v0 is the initial velocity, g is the gravitational acceleration (usually 9.8 m/s²), h is the height, and θ is the angle of launch.

2. Can I use this formula for any projectile motion?

Yes, this formula can be used for any projectile motion as long as the initial velocity is the only unknown variable. However, keep in mind that air resistance and other external factors may affect the actual trajectory of the object.

3. What units should I use for the height and distance in the formula?

In order for the formula to work correctly, the height and distance should be in the same unit of measurement. It is recommended to use meters (m) as it is a standard unit in the metric system.

4. How do I determine the angle of launch for the object?

The angle of launch can be determined by using trigonometry and the known values of the height and distance. You can use the inverse tangent function (tan-1) to find the angle. Alternatively, you can use a protractor to measure the angle if you have a physical object.

5. Is there a simpler way to find the initial velocity without using this formula?

Yes, if you have data on the time taken for the object to travel a known distance, you can use the equation v0 = d / t, where v0 is the initial velocity, d is the distance, and t is the time taken. However, this method may not be as accurate as using the formula mentioned above.

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