# Magnetic Launcher HW: Find Constant Current Flow

• Angie K.
In summary, the problem involves a projectile launcher consisting of a loop of conducting rails, a power supply, and a metal bar in a magnetic field. The goal is to find the required constant current flow in order for the bar to reach a velocity of 30 m/s in a distance of 1.0 m. Using Newton's second law and the kinematic relation v^2 = 2ax, the magnetic force on the bar can be determined. The attempt at a solution involved using the equation F = I*B*L, but this did not work. The kinematic equation was also used, resulting in a velocity of 7.746, but it is unclear how this value was obtained. Further steps are needed to solve the problem
Angie K.

## Homework Statement

A sort of 'projectile launcher' is shown in the figure above. A large current moves in a closed loop composed of fixed conducting rails, a power supply, and a very light, almost frictionless metal bar touching the rails. A magnetic field is perpendicular to the plane of the circuit. If the bar has length L = 15.5 cm, mass m = 1.44 g, and is placed in a field of 1.96 T, what constant current flow is needed in order for it to accelerate to 30 m/s in a distance of 1.0 m?

•Start by finding the magnetic force on the bar, which determines its acceleration via Newton's second law F = ma.
•The kinematic relation v2 = 2ax may be helpful (where v is the velocity attained by an object having acceleration a over a distance x.)

## Homework Equations

F = I*B*L (current, magnetic field, length)

F = m*a

v^2 = 2ax where v is the velocity of object with an acceleration of a/x and x being the distnace

## The Attempt at a Solution

F = I*B*L
43.2 = I*(1.96T)(15.5*10^-2cm)
I tried solving for I that way, which didn't work

I tried the velocity using the v^2 = 2ax equation that was given and I got 7.746

But I'm not quite sure what to do with this.

Where does the value 43.2 come from? You need the kinematics to find F.
Angie K. said:
I tried the velocity using the v^2 = 2ax equation that was given and I got 7.746
7.746 what? And how did you get it?

## 1. How does a magnetic launcher work?

A magnetic launcher uses the principles of electromagnetism to launch objects using a magnetic field. A current is passed through a coil of wire, creating a temporary magnetic field. This field interacts with a permanent magnet, providing the necessary force to launch the object.

## 2. What is the constant current flow in a magnetic launcher?

The constant current flow in a magnetic launcher refers to the steady flow of electrical current through the coil of wire. This ensures a consistent and reliable magnetic field for the launcher to work properly.

## 3. What is the significance of finding the constant current flow in a magnetic launcher?

Finding the constant current flow is important because it allows us to determine the strength of the magnetic field produced by the launcher. This information is crucial for calculating the necessary force to launch an object and for optimizing the design of the launcher.

## 4. How is the constant current flow measured in a magnetic launcher?

The constant current flow can be measured using an ammeter, which is a device that measures the flow of electrical current. The ammeter is connected in series with the coil of wire in the launcher, allowing it to measure the current passing through the coil.

## 5. What are some real-world applications of magnetic launchers?

Magnetic launchers have a variety of applications, including launching spacecraft, accelerating particles in particle accelerators, and launching projectiles in military weapons. They can also be used in transportation systems, such as magnetic levitation trains.

• Introductory Physics Homework Help
Replies
12
Views
283
• Introductory Physics Homework Help
Replies
11
Views
1K
• Introductory Physics Homework Help
Replies
4
Views
447
• Introductory Physics Homework Help
Replies
7
Views
321
• Introductory Physics Homework Help
Replies
1
Views
206
• Introductory Physics Homework Help
Replies
1
Views
457
• Introductory Physics Homework Help
Replies
2
Views
372
• Introductory Physics Homework Help
Replies
7
Views
1K
• Introductory Physics Homework Help
Replies
25
Views
349
• Introductory Physics Homework Help
Replies
49
Views
3K