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Physics Solver | Projectile into Block

February 19, 2015 · by physics · Bullets, Physics Help, Physics Problem Solver

Problem:

You set up a ballistic pendulum in order to conduct the experiment. The pendulum is made of a block of wood suspended from a set of strings. You fire the bullet into the stationary block and measure the speed at the combined bullet and block since the bullet lodges inside the block. I certainly would like to see these kids shoot a gun into the block, here for the experiments. I don’t know. You measure the mass of the bullet to be 4.2 grams, the mass of the block to be 500 grams, and the speed at the combined bullet and block to be 6.75 meters per second. Calculate the speed of the bullet (muzzle speed) and give your answer in meters per second.

Raw Transcripts

This is Tom from everystepphysics.com and everystepcalculus.com I’m going to an experimental problem in physics that they give you to experiment with in doing the lab class. And let’s get started. You set up a ballistic pendulum in order to conduct the experiment. The pendulum is made of a block of wood suspended from a set of strings. You fire the bullet into the stationary block and measure the speed at the combined bullet and block since the bullet lodges inside the block. I certainly would like to see these kids shoot a gun into the block, here for the experiments. I don’t know. You measure the mass of the bullet to be 4.2 grams, the mass of the block to be 500 grams, and the speed at the combined bullet and block to be 6.75 meters per second. Calculate the speed of the bullet (muzzle speed) and give your answer in meters per second. So, let me show you how my program would do for this lab thing in your homework a little bit, maybe. Physics to get to my menu. Scroll down to bulletin and pendulum which is the subject matter here. And we’re gonna wait for load. Notice when things are loading, you get a busy signal.here on your calculator indicating that is loading. And if it’s a long program like this one take a little bit in my but only once. After that, it loads very quickly. And they the bullet is going to embed into the block or the wood. So it’s, bullet in. We’re going to choose that one. And we want to get initialvelocity of the bullet. We’re going to choose that. And they give you instead of height, sometimes they give you height which there’s a way of calculating that and there’s also the velocity block and bulllet. So that’s what they’re giving, choose number two. You can choose the numbers before these items. And we’re gonna enter the mass. You have to press Alpha before you enter anything in here. Alpha 4.2 is given, 4.2 grams. It’s a very small bullet. And the 2 is here I just haven’t indicated it but it’s still in the calculations.  And then we’re going into the mass of the block. Alpha 500 grams goes here. And the final velocity is alpha 6.75 meters per second, number three. In the positive direction. I always show what you’ve entered so you can change it in case you made a mistake and don’t like it. I say it’s okay. And here’s the calculations, here’s the formula. All the variables are put in. Notice it’s very clear. Initial velocity of one. Notice initial velocity, the used ot have a lot over professors use VO, which meant original velocity. But now lately they’ve been using initial and I like initial. And of course one is the bullet and two would be the block and bullet. I make everything clear of what in my programs of what I’m talking about. It always bugged me in physics that they throw around letters and minus signs and everything else and you don’t know what is going on. But in my programs , you do. Here’s the calculations. Here it is110 meters per second. Pretty neat, huh? EveryStepPhysics.com Thank you