A rocket moves upward, starting from rest with an acceleration of

In summary, a rocket moves upward by expelling hot gas out of its engines, following Newton's third law of motion. It typically starts from rest on the ground and its acceleration is determined by the thrust of its engines. The acceleration directly affects its speed, but once it reaches its maximum speed, it will maintain a constant speed unless more thrust is applied. It is not possible for a rocket to move upward without acceleration as it needs to overcome the force of gravity.
  • #1
lettertwelve
54
0

Homework Statement



A rocket moves upward, starting from rest with an acceleration of 29.0 m/s^2 for 8.00 s. It runs out of fuel at the end of the 8.00 s but does not stop. How high does it rise above the ground? (in meters)


Homework Equations



deltaX=(1/2)final velocity * change in time ?

The Attempt at a Solution




i really don't understand which of the equations of straight-line motion would be relevant, and how, for example: 29m/s^2 is DIFFERENT than just 29m/s
 
Physics news on Phys.org
  • #2
Yes, 29.0 is the acceleration not velocity... what are your displacement equations for uniform acceleration?
 
  • #3
.

I would approach this problem by first identifying the known and unknown variables. The known variables are the starting velocity (0 m/s), acceleration (29.0 m/s^2), and time (8.00 s). The unknown variable is the final velocity, which we can solve for using the equation vf = vi + at, where vf is the final velocity, vi is the initial velocity, a is the acceleration, and t is the time.

Using this equation, we can calculate the final velocity of the rocket after 8.00 s to be 232.0 m/s. However, since the rocket runs out of fuel at this point, it will continue to move upward with a constant velocity of 232.0 m/s until it reaches its maximum height.

To calculate the maximum height, we can use the equation hf = hi + vit + (1/2)at^2, where hf is the final height, hi is the initial height (in this case, 0 m), vi is the initial velocity, a is the acceleration, and t is the time. Plugging in the values, we get hf = 0 + (0)(8.00) + (1/2)(29.0)(8.00)^2 = 928.0 m.

Therefore, the rocket will rise to a maximum height of 928.0 meters above the ground. It is important to note that the units for acceleration are m/s^2, which represents a change in velocity over a period of time, while m/s represents a constant velocity. This is why 29.0 m/s^2 is different than just 29.0 m/s.
 

1. How does a rocket move upward?

A rocket moves upward by expelling hot gas out of its engines at high speeds, according to Newton's third law of motion which states that for every action, there is an equal and opposite reaction. As the gas is forced out of the rocket, it pushes the rocket in the opposite direction, causing it to move upward.

2. What is the starting position of a rocket when it moves upward?

A rocket typically starts from rest on the ground before it begins to move upward. This is because the force of gravity is acting on the rocket, keeping it stationary until the engines are ignited and the rocket begins to accelerate.

3. What is the acceleration of a rocket when it moves upward?

The acceleration of a rocket when it moves upward is determined by the thrust of its engines. The higher the thrust, the greater the acceleration will be. However, other factors such as air resistance and the weight of the rocket also play a role in determining the acceleration.

4. How does the acceleration of a rocket affect its speed?

The acceleration of a rocket directly affects its speed. As the rocket accelerates upward, its speed increases. The longer the rocket is accelerating, the faster it will go. However, once the rocket reaches its maximum speed, it will stop accelerating and maintain a constant speed unless more thrust is applied.

5. Can a rocket move upward without acceleration?

No, a rocket cannot move upward without acceleration. In order for the rocket to overcome the force of gravity and move upward, it needs to have a net acceleration in the upward direction. Without acceleration, the rocket would remain stationary or fall back to the ground.

Similar threads

  • Introductory Physics Homework Help
Replies
14
Views
731
  • Introductory Physics Homework Help
Replies
2
Views
757
  • Introductory Physics Homework Help
Replies
13
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
883
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
13
Views
879
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
763
  • Introductory Physics Homework Help
Replies
2
Views
957
Back
Top