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course Phy 201
One lab activity:Conservation of Energy on a Ramp
Use an incline with a very small slope.
Strike the steel ball so it coasts up, comes to rest, then accelerates back down the incline. Let the ball continue to roll off the incline and fall to the floor, and mark the position at which it hits the floor. (Be sure you also mark the straight-drop position).
Also note the position on the incline at which the ball comes to rest before accelerating back down.
At the same time, using the TIMER program, record the time interval from the end of the 'strike' back to the end of the incline.
Repeat for at least two good trials.
Report your data:
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Ramp Slope
.5cm
Ramp length
30cm
Up the Incline Timer
1.761
2.041
21cm
27cm
Down the Incline Time
2.794
2.513
Down the Incline straight down position
12cm
Down the Incline drop position
10cm
11.5cm
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From each of the stopping points on the ramp, as you previously observed them, release the ball from rest and time it down the incline. Record the positions at which it strikes the floor.
Report your data:
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Down the Incline Time
2.794
2.513
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From your data, infer how long it took the ball to go up the ramp for each trial.
Calculate the ball's acceleration up the ramp, and its acceleration down the ramp.
Report your results, and indicate how they were obtained:
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Up the Incline Timer
1.761
2.041
21cm
27cm
21/1.716=11.92cm/s
27cm/2.041=13.22cm/s
These are average velocities. You still need to find the accelerations.
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From your two accelerations, you can infer the coefficient of rolling friction. What is your result?
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Wt=slope*wt
Wt=.05 *55mg
Wt=27.5mg
you first need to get the up and down values of the acceleration
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The large ball has diameter 2.5 cm, the small ball diameter 2.0 cm. The ball is made of steel with an approximate density of 8 grams / cm^2.
Find the KE the ball attained while rolling down the ramp with the PE it lost while rolling down. Compare the two:
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Ke=1/2mv^2
Ke=½(8g)(2.5)^2
KE=25g/cm^2
PE=mgh
PE=(8grams / cm^2)(9.8m/s^2)(2.5)
PE=1920.8
It's not clear what the 2.5 means or how it's connected to your data.
Can you clarify?
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Calculate the energy lost to rolling friction. What do you get?
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That the energy is greater lost than friction.
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Can you account for all PE that was lost as the ball rolled down the ramp? Give details.
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Other than fritcition that would be my only guess.
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