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Thank you We sneak and here's your shmoop douceur brought

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to you by game shows they're all fun and games

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until well who are we kidding that's all they are

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spun in games Check the following diagram Ernie is walking

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around new york and suddenly finds himself on a game

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show that tests the physics knowledge of random passers by

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The host shows ernie the force time diagram above which

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is based on the motion of a two kilogram stone

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that rules across ah horizontal surface He asks what is

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the velocity of the stone at twelve seconds and hear

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potential answers Yeah all right well let's look at our

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diagram here We're dealing with a force time diagram Anytime

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we see force in time together like this we know

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we're dealing with impulse Impulse equals force applied over an

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interval of time and impulses equal toe linear momentum and

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momentum Well it's the product of mass and velocity Right

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To find the total impulse in a diagram like this

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we need to calculate the area under the curve right

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there We can make that easier by breaking the diagram

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into two triangles and a rectangle like this Now we

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only need the area for the first triangle and the

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rectangle Since we need to know the velocity at twelve

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seconds we could do a little old school geometry to

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figure those out The area of the triangle is twenty

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In the area of the rectangle is sixty giving us

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a total impulse of lady Well now we can just

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put the numbers we have into the equation in salt

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for velocity with the impulse which is eighty equals two

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kilograms times velocity When we do the math we see

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that the velocity is forty meters per second making option

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b the correct answer Just to be safe we'll be

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sure to remember how to figure out impulse in case

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wherever ambushed on the street by some physics crazed game 00:02:02.69 --> [endTime] show

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