hope this helps you Sara
The purpose of this lab is to create an inelastic collision setup (using an air track or frictionless surface) and find the change in momentum after the object collides with a force sensor. The amount of momentum (p) an object has is based on its mass (m) and velocity (v). Anything with mass that is moving has momentum, as momentum is the product of the two. Momentum can be found using the following equation:
p = m * v
Momentum is measured in kilogram meters per second (kg * m/s). Because momentum relies on velocity which has magnitude and direction, then momentum must also have magnitude and direction, making it a vector quantity. In a collision, an object experiences a force for a specific amount of time which results in a change in momentum (known as an impulse). The impulse causes (and is equal to) the change in momentum. An impulse is a change in velocity over a period of time (a change in momentum). An impulse is the product of the average force exerted by an object and the time interval during which that force acts:
Impulse
Impulse is measured in Newtons/second. This lab will undergo an inelastic collision, because there are bumpers on the end of each glider, and more momentum will further be lost by the collision and movement of the force sensors.
One might hypothesize that the change in momentum might be about .005N*s.
Materials and Methods:
-Air track system (bumpers, track, etc.)
-Air Source/compressor (to pull in air and force it into air track so a frictionless surface can be made)
-Air Hose (attaches to air source/compressor to direct air into track)
-several gliders of different weights
-ruler (or measure on the side of air track)
-collision/force detectors (measure force vs. time)
-LabPro interface
Step one of this lab is to set up an collision situation using the weighted gliders and sensors (force sensors only) on an air track. The sensors must be set a known distance apart and the weight of the gliders must be known or calculated (this way velocity and momentum can later be calculated). Once set up, turn on the air source/compressor, push the glider and start the data collection. After the collisions, turn the compressor off, and stop the data collection. Now that the data has been collected, find the change in momentum using physics (i.e. impulse-momentum, etc). The mass of each glider can be found by simply weighing it. The velocity can be found by finding each gliders change in distance divided by the change in time. For this lab, it was determined that a second glider was not necessary because momentum is conserved, so the initial and final momentum of two gliders colliding should be the same as one glider colliding. Change in momentum can also be found using the fact that the impulse is the same as (the integral of the force and time) rather than finding the individual velocities and mass.
Results:
Change in time: .0028s
Average Force: .07443 N
Impulse = Change in momentum = = = .0002084 N*s
Discussion:
Using data collected from the software, the time that force was applied the sensor (the sensor it first collided with) could be found along with the force (which we can calculate the average force from). By multiplying the average force by the change in time, the impulse, which is also the change in momentum, can be found. This is the same as finding the integral of the force in terms of time, . The impulse is equal to the change in momentum because when a force is applied then absorbed or given away, the object loses some of it’s force, and therefore a decrease in the momentum. The change in momentum would be the amount of momentum that the object would lose due to the collision, which is .0002084 N*s in the case tested. This number, however, would vary greatly depending on the mass of a given object and its velocity. Had this glider been given a lower velocity, it would have a smaller change in momentum more than likely.
My hypothesis that the change in momentum would be approximately .005 was well off. The actual change in momentum was only about .0002, one-tenth of that.
p = m * v
Momentum is measured in kilogram meters per second (kg * m/s). Because momentum relies on velocity which has magnitude and direction, then momentum must also have magnitude and direction, making it a vector quantity. In a collision, an object experiences a force for a specific amount of time which results in a change in momentum (known as an impulse). The impulse causes (and is equal to) the change in momentum. An impulse is a change in velocity over a period of time (a change in momentum). An impulse is the product of the average force exerted by an object and the time interval during which that force acts:
Impulse
Impulse is measured in Newtons/second. This lab will undergo an inelastic collision, because there are bumpers on the end of each glider, and more momentum will further be lost by the collision and movement of the force sensors.
One might hypothesize that the change in momentum might be about .005N*s.
Materials and Methods:
-Air track system (bumpers, track, etc.)
-Air Source/compressor (to pull in air and force it into air track so a frictionless surface can be made)
-Air Hose (attaches to air source/compressor to direct air into track)
-several gliders of different weights
-ruler (or measure on the side of air track)
-collision/force detectors (measure force vs. time)
-LabPro interface
Step one of this lab is to set up an collision situation using the weighted gliders and sensors (force sensors only) on an air track. The sensors must be set a known distance apart and the weight of the gliders must be known or calculated (this way velocity and momentum can later be calculated). Once set up, turn on the air source/compressor, push the glider and start the data collection. After the collisions, turn the compressor off, and stop the data collection. Now that the data has been collected, find the change in momentum using physics (i.e. impulse-momentum, etc). The mass of each glider can be found by simply weighing it. The velocity can be found by finding each gliders change in distance divided by the change in time. For this lab, it was determined that a second glider was not necessary because momentum is conserved, so the initial and final momentum of two gliders colliding should be the same as one glider colliding. Change in momentum can also be found using the fact that the impulse is the same as (the integral of the force and time) rather than finding the individual velocities and mass.
Results:
Change in time: .0028s
Average Force: .07443 N
Impulse = Change in momentum = = = .0002084 N*s
Discussion:
Using data collected from the software, the time that force was applied the sensor (the sensor it first collided with) could be found along with the force (which we can calculate the average force from). By multiplying the average force by the change in time, the impulse, which is also the change in momentum, can be found. This is the same as finding the integral of the force in terms of time, . The impulse is equal to the change in momentum because when a force is applied then absorbed or given away, the object loses some of it’s force, and therefore a decrease in the momentum. The change in momentum would be the amount of momentum that the object would lose due to the collision, which is .0002084 N*s in the case tested. This number, however, would vary greatly depending on the mass of a given object and its velocity. Had this glider been given a lower velocity, it would have a smaller change in momentum more than likely.
My hypothesis that the change in momentum would be approximately .005 was well off. The actual change in momentum was only about .0002, one-tenth of that.