Since I need to solve this quickly, i'll post here too

[wsbkp08]

Since I need to solve this quickly, i'll post here too!

Homework Statement

Hi, guys.
I did a project but questions are killing me right now.
I was going all the tutorials but I really have no idea.
What we did was water rocket project.
Here are the data
Ttotal - avg. 9.96 sec.
Avg. Apogee - 2.94 sec.

Homework Equations

The Attempt at a Solution

I need to find the v initial, ymax, and the maximum range.
Here is how I did it

For Vinitial
DeltaY(0) =(Vinitial)(5.88)+(1/2)(-9.8)(5.88)^2
Vinital = 28.8m/s
5.88sec comes from avg. apogeeX2 ------> (2.94)(2)

For Ymax,
Ymax= (Vinital)(time)+(1/2)(-9.8)(time)
(28.8)(2.94)+(1/2)(-9.8)(2.94)^2
= 42.3 m

For maximum Range,
I found out that cos 45 will give me maximum range so

Range=(Vinital)(cos45)(time)
(28.8)(cos45)(5.88)
= 119.7 m

Lastly, my teacher asked, "What role does the water play in making the rocket move?"
He also asked for relevant formulas and a diagram illustrating the forces.
Only thing we learned so far are Horizontal Projectil motion and free fall.
I do not think we ever learned this.
Can you please help me with this? I've been working for entire day!
Thanks guys.

 

[jbsteele]

The role of water in making the rocket move is to provide thrust. When the water is released from the rocket, it pushes against the air and creates a reaction force which propels the rocket forward. This reaction force is what causes the rocket to move. The relevant formula is Newton's Third Law of Motion which states that for every action there is an equal and opposite reaction. The diagram illustrating the forces would look something like this: [Diagram of Forces] The blue arrow represents the reaction force of the water pushing against the air, while the red arrows represent the gravitational force on the rocket.

 

[thomate1]

Hello there,

I understand that you are struggling with your water rocket project and need to find the initial velocity, maximum height, and maximum range. It seems like you have made some good efforts in solving these problems. However, I would suggest double-checking your calculations to make sure they are correct.

As for your teacher's question about the role of water in making the rocket move, it is an important factor in the launch of the rocket. The water is used as a propellant and is expelled out of the rocket through the nozzle, creating thrust and propelling the rocket upward. This can be explained by Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. In this case, the action is the expulsion of water, and the reaction is the upward movement of the rocket.

In terms of relevant formulas, you can use the rocket equation, which relates the mass of the rocket, the mass of the propellant (water), and the change in velocity of the rocket. You can also use Newton's second law of motion, which states that the net force acting on an object is equal to its mass multiplied by its acceleration. In this case, the net force is the thrust from the water, and the acceleration is the change in velocity of the rocket.

I hope this helps you in your project. Keep up the good work and don't hesitate to ask for help if you need it. Good luck!