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8

Other Suggested Experiments

 

Launch from a Force Sensor

Set up an end stop, a force sensor, and the release pin as illustrated. While recording 
motion- and force-sensor data, pull the force sensor to compress the spring; then jerk 
out the release pin to launch the cart. In this way, you can record compression dis-
tance, spring force, and launch velocity in a single data run.

Launch from a Hanging Mass

Important: Do not use precision masses in this activity. Instead, use a small sandbag or other 
object that will not be damaged when dropped.

Set up an end stop, a Super Pulley, a string, and the release pin as illustrated. Hang an 
object of known mass (up to about 500 g) from the string. Jerk the pin out to launch 
the cart. The spring force is equal to the weight of the hanging object.

Collision with a Fixed Object

Set up a track with an end stop at one end and a motion sensor at the other end. Set the 
sampling rate to 50 Hz. Start data recording. Give the cart a push to make it roll along 
the track and bounce off the end stop. Stop data recording. 

Hold the cart stationary with the spring just touching the end stop and record a second 
data run to measure the “zero-compression” position.

Use the velocity data to determine the kinetic energy of the cart before and after the 
collision. Use the position data to determine the maximum spring compression (that 
is, the maximum position measured during the collision minus the position measured 
when the spring was just touching the end stop). From the compression distance, cal-
culate the maximum potential energy stored in the spring.

In this collision, energy is transferred from kinetic energy to potential energy and 
back to kinetic energy. At each step, how much energy is “lost?” Where does it go?

Velocity before

Velocity after

“Zero-compression”

position

Maximum

compression

Summary of Contents for ME-6843

Page 1: ...n many of the PASCO dynamics systems See PASCO catalog or www pasco com for details 1 ME 6951 ME 6950 ME 9430 or ME 9454 Track2 1 ME 6953 or similar End Stops3 3 New style plastic end stops required These are included with PASCO dynamics systems starting in 2007 2 ME 9469 2 pack Recommended Equipment 250 g Compact Cart Mass 2 ME 6755 For sensor based method Motion Sensor4 4PASPORT sensors require ...

Page 2: ...ck and two adjustable end stops 1 Fit the Spring Cart Launcher onto the top of the cart as illus trated Tighten the thumbscrews to secure it 2 Select one of the included springs Slide it onto the launcher shaft with the flared end out Turn the spring to secure the end in the spring retention hole as illustrated 3 Tie the string to the release pin 4 Install two end stops near one end of a dynamics ...

Page 3: ...sition x1 to x2 the work that you do is equal to the area under the Fx versus x graph or eq 2 The potential energy stored in a spring is eq 3 The kinetic energy of a cart moving on a track is eq 4 where m is the mass of the cart and V is the magnitude of velocity The change in gravitational potential energy of a cart moving up an inclined track is eq 5 where g 9 8 m s2 s is the distance traveled a...

Page 4: ... stop on the track If you are using a 1 2 m track place the end stop near one end If you are using a 2 2 m track place the end stop in the middle 3 Level the track so that the cart does not roll when release from a standstill 4 Clip the motion sensor to the end of the track opposite from the end stop Aim the sensor along the track Set the range switch to the NEAR or cart setting 5 Connect the moti...

Page 5: ...all three springs Untie the string from the launcher shaft for the next part Spring Potential Energy and Kinetic Energy In this part you will study the relationship between the potential energy initially stored in the spring and the kinetic energy of the cart just after launch 1 Place a second end stop on the track about 8 cm behind the first end stop 2 Place the cart on the track with the launche...

Page 6: ...ps 1 through 3 on page 2 2 Install an end stop about 20 cm from the end of the track 3 Clamp a pulley to the same end of the track 4 Position the track so that a mass hanging from the pulley is free to hang over the edge of your lab bench 5 Level the track so that the cart does not roll when release from a standstill 6 Place the cart on the track with the launcher shaft through the hole in the end...

Page 7: ...sition of the cart as x2 5 Pull out the release pin with a quick jerk 6 Watch the cart carefully as it ascends the track Observe the highest position achieved Try to read it to the nearest centimeter Record this position as x3 7 Calculate the spring compression x x1 x2 8 Use x the value of k that you found in the previous part and Equation 3 to calcu late the initial potential energy of the spring...

Page 8: ...llision with a Fixed Object Set up a track with an end stop at one end and a motion sensor at the other end Set the sampling rate to 50 Hz Start data recording Give the cart a push to make it roll along the track and bounce off the end stop Stop data recording Hold the cart stationary with the spring just touching the end stop and record a second data run to measure the zero compression position U...

Page 9: ...ithout the written con sent of PASCO scientific is prohibited Trademarks PASCO PASCO scientific DataStudio PASPORT and ScienceWorkshop are trademarks or registered trademarks of PASCO scien tific in the United States and or in other countries All other brands products or service names are or may be trademarks or service marks of and are used to identify products or services of their respective own...

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