Roller coaster mock Lab Report

[DelusionRemedy]

Homework Statement

Lab report calculations and clarifications

Relevant Equations

"kinematics equations"

I wasn't sure if this would go here but I'm currently struggling with how I'm doing specific calculations. In this lab we had to make a roller coaster that has two loops and cut off at the bottom to allow flight time.
The angle that the marble(5g) came off was at 40 deg and was a height of 0.44m. I have the initial and final velocity of the marble during the roller coaster but don't know if I'm using the final velocity as my initial for the time of flight calculation once it starts to fall.

 

[erobz]

Homework Statement: Lab report calculations and clarifications
Relevant Equations: "kinematics equations"

I wasn't sure if this would go here but I'm currently struggling with how I'm doing specific calculations. In this lab we had to make a roller coaster that has two loops and cut off at the bottom to allow flight time.
The angle that the marble(5g) came off was at 40 deg and was a height of 0.44m. I have the initial and final velocity of the marble during the roller coaster but don't know if I'm using the final velocity as my initial for the time of flight calculation once it starts to fall.

You can draw a diagram of your setup and upload it as a picture for starters.

 

[DelusionRemedy]

Hopefully that’s a good enough diagram

 

[erobz]

Hopefully that’s a good enough diagram
View attachment 361711

It's not great, but it's something. So you are asking to find the velocity of the marble as it leaves the end of the track if it were to make both loops (the initial velocity for the projectile motion phase)?

 

[DelusionRemedy]

I’m not quite sure, that’s where I get stuck too. I had to find the initial and final velocity for the coaster part itself if the marble goes through both loops, which I have but now I need to find initial velocity of it going into ‘flight to help find the flight time. I’ll attach an image of what my teacher says.

 

[erobz]

I’m not quite sure, that’s where I get stuck too. I had to find the initial and final velocity for the coaster part itself if the marble goes through both loops, which I have but now I need to find initial velocity of it going into ‘flight to help find the flight time. I’ll attach an image of what my teacher says.

You seem to be saying you have computed the velocity at the end of the track, but you are unsure of how to find the time of flight using the equations of projectile motion with that velocity?

 

[DelusionRemedy]

You seem to be saying you have computed the velocity at the end of the track, but you are unsure of how to find the time of flight using the equations of projectile motion with that velocity?

If I’m understanding that correctly then yes!

 

[erobz]

If I’m understanding that correctly then yes!

Ok, what do your lecture notes say about it? You have to be able to say something about the application of projectile motion equations to this problem at this stage.

 

[Steve4Physics]

@DelusionRemedy, a few thoughts in addition to what @erobz has said ...

On your diagram you give the total height as ‘0.2794 m’. That suggests you measured the height to the nearest 0.1 mm which doesn’t sound right.

If your 5 g marble was made of glass (marbles usually are) with a typical density of say 2.5 g/cm^3, its volume would be 2 cm^3. This would mean its diameter was about 1.56 cm which is even bigger than the diameter of the first loop – is that right?

I have the initial and final velocity of the marble during the roller coaster but don't know if I'm using the final velocity as my initial for the time of flight calculation once it starts to fall.

There are 2 parts to the marble’s journey: part-1 is along the track, part-2 is the 'flight’ in air. The final velocity from part-1 is the initial velocity for part-2.

Edits.

 

[kuruman]

Hopefully that’s a good enough diagram

Better than any hand-made drawing would be a photograph or two from different angles. A short video, if you can manage it, would also be helpful. You know what the marble's moton looks like, but we don't.

Also, be mindful that glass marbles on steep inclines tend to roll and slip at the same time. This complicates the calculation of the marble's velocity at the end of the track.