Calculating BB Gun Muzzle Velocity Using Projectile Motion Equations

In summary, the conversation discusses a student's experiment to measure the muzzle velocity of a pellet shot from a gun. The position of the pellet is given by y = Ax^2, where A is a constant. The constant A can be expressed in terms of the initial velocity v and free-fall acceleration g. The initial velocity is assumed to be constant and the equation for y is corrected to y=x^2[g/(2vi^2)]. The conversation ends with the student thanking for the help.
  • #1
blackboy
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0

Homework Statement



A student decides to measure the muzzle velocity of a pellet shot from his gun. He points the gun horizontally. He places a target on a vertical wall a distance x away from the gun. The pellet hits the target a vertical distance y below the gun.
(a) Show that the position of the pellet when traveling through the air is given by y = Ax^2, where A is a constant.
(b) Express the constant A in terms of the initial velocity v and the free-fall acceleration g.
(c) If x = 3 m and y = 0.21 m, what is the initial speed of the pellet?

Homework Equations


The Attempt at a Solution


Can I assume vi is constant? For (a) I got y=x^2[g/(2vi^2)]. Is vi a constant? If so then I know to do it. If not can you help? Thanks.
 
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  • #2
The initial velocity is of a given magnitude and direction. While instantaneous velocity might change, the initial velocity is just a constant. Your equation, however, is almost correct, but not quite.
 
  • #3
Hmm I tried it over and I still get the same answer. What did I do wrong?
 
  • #4
O,so sorry, you are correct, I was reading your equation incorrectly.
 
  • #5
Ok thanks for your help.
 

What is BB Gun Muzzle Velocity?

BB gun muzzle velocity refers to the speed at which a BB pellet is propelled out of the barrel of a BB gun. It is typically measured in feet per second (fps) or meters per second (m/s).

What factors affect BB Gun Muzzle Velocity?

The muzzle velocity of a BB gun can be affected by many factors, including the type and weight of the BB pellets, the power source of the gun (such as CO2 or spring), the length and diameter of the barrel, and any modifications made to the gun.

What is the average muzzle velocity of a BB gun?

The average muzzle velocity of a BB gun can vary greatly depending on the type and power of the gun. Most BB guns have a muzzle velocity between 200-600 fps, with some high-powered rifles reaching speeds of over 1000 fps.

Is there a legal limit for BB gun muzzle velocity?

In most countries, there are laws and regulations regarding the maximum muzzle velocity of a BB gun. In the United States, for example, the maximum muzzle velocity for a BB gun is 700 fps for rifles and 350 fps for pistols.

Can BB gun muzzle velocity be increased?

Yes, it is possible to increase the muzzle velocity of a BB gun through various modifications such as upgrading the spring or adding a longer barrel. However, it is important to follow all laws and regulations when modifying a BB gun and to always use proper safety precautions.

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