Purpose: Determine the firing speed of a ball from a spring-loaded-gun.
Model: vombullet=vfmtotal, 1/2gt^2=h, x=vft, and 1/2mtotalvf^2=(1-cosθ)Lmtotalg
vo is the velocity of the bullet flying out the barrel, mbullet is the mass of the bullet, vf is the velocity of the block-bullet, t is the time that the bullet hit the ground, h is the heigh from the barrel to the ground, X is the distance from the barrel to the hit point on the ground, θ is the angle the pendulum hit the highest point, and L is long of the string.
Purpose: We measure and record the mass of the bullet mbullet and block mblock, mbullet=0.0075kg and mblock=0.0795kg. We determine the length of the string of the pendulum L, L=0.205m. We level the base of the apparatus to make the barrel can fire horizontally and make sure the block is level.
After making sure the bullet can hit the block and strick into the block, we pull back and lock the spring into the first notch, put the angle indicator to zero degress, and place the ball into the barrel.
We push the locker and fire the bullet into the block. The block push the angle indicator back. We read and record the maximum angle θ, θ=33°.
Then, we determine the heigh from the barrel to the ground h, h=0.99m. Without the block, we fire the bullet. it fly and hit the ground. We use the carbon record paper to mark the hit point. Then, we determine the horizontal distance between the barrel and the hit point x, x=2.36m
Then,
vo1 is the initial velocity of the bullet which we gets by shooting the bullet to the ground
1/2gt^2=h
t=0.449s
vo1t=x
vo1=5.25m/s
vo2 is the initial velocity of the bullet which we gets by shooting the bullet into the block
vo2mbullet=vfmtotal
1/2mtotalvf^2=(1-cosθ)Lmtotalg
vf=0.492m/s
vo2=5.71m/s
We get vo1≈vo2, considet that the uncertainty for every data that we determine. We assume they are the same.
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