Solving for Launch Speed and Height of a Toy Rocket

Click For Summary

Homework Help Overview

The problem involves a toy rocket moving vertically upward, passing a window at a specific height. Participants are tasked with determining the launch speed of the rocket and its maximum height, given certain parameters such as the time taken to pass the window and the height of the window above the ground.

Discussion Character

  • Exploratory, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss calculating the final velocity using the time taken to travel the height of the window and question the validity of their results. Some express confusion about the methods suggested and seek clarification on the equations involved.

Discussion Status

The discussion is ongoing, with participants exploring various equations of motion and attempting to relate the known variables to find the unknowns. Some guidance has been offered regarding the use of kinematic equations, but there is no consensus on the correct approach, and further clarification is needed by some participants.

Contextual Notes

Participants mention the acceleration due to gravity and the need to account for multiple distances in their calculations. There is a noted lack of understanding regarding the explanations provided, indicating potential gaps in foundational knowledge or clarity in the discussion.

homeworkboy
Messages
35
Reaction score
0
A toy rocket moving vertically upward passes by a 2.2 m high window whose sill is 9.0 m above the ground. The rocket takes 0.14 m/s} to travel the 2.2 m height of the window.

What was the launch speed of the rocket? Assume the propellant is burned very quickly at blastoff.

How high will the rocket go?
 
Physics news on Phys.org
bump please help
 
homeworkboy said:
A toy rocket moving vertically upward passes by a 2.2 m high window whose sill is 9.0 m above the ground. The rocket takes 0.14 m/s} to travel the 2.2 m height of the window.

What was the launch speed of the rocket? Assume the propellant is burned very quickly at blastoff.

How high will the rocket go?

What do you think you should do to solve the problem?
 
well since it says it tokk .14 sec to travel 2.2 m then velocity (v) = 2.2/.14 then we get the final velocity...we know a = -9.8 m/s2...and X = 2.2+9 =11.2m...so we find initial velocity but it says that its the wrong answer

so if u teach me the method it would be great...
 
homeworkboy said:
well since it says it tokk .14 sec to travel 2.2 m then velocity (v) = 2.2/.14 then we get the final velocity...we know a = -9.8 m/s2...and X = 2.2+9 =11.2m...so we find initial velocity but it says that its the wrong answer

so if u teach me the method it would be great...

You need to use the relationship that Vf2 - Vi2 = 2 a x where a is 9.8 m/s2

You are given 2 distances here. Choose one formula from launch.

Vo2 - Vb2 = 2 a x ... where Vb is V bottom and x is height to bottom of window which is 9

You also know that since gravity is slowing things down that
Vb = Vt + .14 (9.8) where Vt is velocity at the top of the window.

Then you can make use of the other equation to the top of the window:
Vo2 - Vt2 = 2 a x ... where Vt is V top and x is height to top of the window which is 11.2

3 equations. 3 unknowns. Solve.
 
Last edited:
I dint understand your explanation...is there anyone else who can help me..
 
bump...anyone
 
homeworkboy said:
I dint understand your explanation...is there anyone else who can help me..

What have you tried? You have some of the values. And you have 3 equations that relate the variables you don't have to each other.

You need to use algebra to solve the equations and eliminate your unknowns.
 

Similar threads

Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
7K
Replies
6
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
13
Views
2K
Replies
13
Views
2K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 25 ·
Replies
25
Views
19K
  • · Replies 2 ·
Replies
2
Views
5K