Work-Energy Theorem: Find Final Speed of Ship

In summary, a spaceship of mass 5.00 x 10^4 kg is traveling at a speed of 1.15 x 10^4m/s with a constant force of 4.00 x 10^5 N from its engine. It moves a distance of 2.50 x 10^6 m in the direction of the engine's force. To determine the final speed of the ship using the work-energy theorem, the work done by the engine in this distance must be equal to the change in kinetic energy of the ship. This can be calculated by using the formula W = Fd, where d is the distance traveled and F is the force applied. To find the final speed, the work must be
  • #1
PhysicsDud
24
0
I'm having trouble with where to begin with this question, if anyone has guidance I'd be grateful.

A spaceship of mass 5.00 x 10^4 kg is traveling at a speed 1.15 x 10^4m/s in outer space. Except for the force generated by its own engine, no other force acts on the ship. As the engine exerts a constant force of 4.00 x 10^5 N, the ship moves a distance of 2.50 x 10^6 m in the direction of the force of the engine.
a) Determine the final speed of the ship using the work-energy Theorem.
 
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  • #2
The work is just a name people gave to "change in kinetic energy". If you find the work "done by the engine" in the ship going a distance of 2.50 x 10^6 m, then you've found the change in kinectic energy of the ship. And work in one dimension is simply

[tex]W =Fd[/itex]

where d is the distance traveled and F the force applied during this travel.
 
  • #3
Thanks, so If I solve for W, I get 1.00 x 10^12, then I make this answer equal to 1/2mv^2 - 1/2mv(o)^2, and plug in everything I have and solve for v, this should give me the correct answer?
 
  • #4
Correct-o-mundo!

Edit: except for the answer to W!
 
Last edited:

What is the Work-Energy Theorem?

The Work-Energy Theorem is a fundamental principle in physics that states that the net work done on an object is equal to the change in its kinetic energy.

How is the Work-Energy Theorem used to find the final speed of a ship?

The Work-Energy Theorem can be applied to a ship by considering the work done by the ship's engines and the work done by external forces, such as friction and air resistance. By equating these two works, we can solve for the final speed of the ship.

What is the equation for the Work-Energy Theorem?

The equation for the Work-Energy Theorem is: W = ΔKE = (1/2)mv2f - (1/2)mv2i, where W is the net work done, ΔKE is the change in kinetic energy, m is the mass of the object, vf is the final velocity, and vi is the initial velocity.

Can the Work-Energy Theorem be applied to all types of motion?

Yes, the Work-Energy Theorem can be applied to all types of motion, including linear, rotational, and simple harmonic motion. It is a general principle that applies to all forms of energy and work.

What are some limitations of the Work-Energy Theorem?

The Work-Energy Theorem assumes that there are no non-conservative forces, such as friction, acting on the object. It also assumes that the mass of the object remains constant and that the work done is only due to external forces. Additionally, the Work-Energy Theorem does not account for changes in potential energy.

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