Pasco Scientific ME-6956, Instruction Manual And Experiment Manual

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PAScar Accessory Track Set (2.2 Meter) 012-07558A
®
If the mass used to accelerate the car is too low,
friction will be a very significant source of error.
If it is too high, then the time will be short and
accurate measurements will be difficult. For this
lab, it would be best to use a photogate timing
system, such as the PASCO ME-9215.
Answers to Questions
1. The results of this experiment generally show
that F = ma. Errors can be high, due to friction
and timing inaccuracy.
2. The force of the hanging weight is larger than
the total mass times acceleration. The difference
between the two is the force of friction.
3. The hanging mass is accelerating at the same
rate as the car, so both the hanging mass and the
car
’ s mass must be considered.
4. The car is on a level track, so it is not acceler-
ated by gravity.
Answers to Questions
1. The initial spring potential energy is larger.
(Generally. There are experimental errors, which
can make the gravitational energy appear larger
than the initial spring potential.) The
“ lost ” en-
ergy goes into friction.
2. Why not? The increased mass means that the car
does not travel as high, but the final gravita-
tional potential energy will be the same.
Experiment 8: Newton’s Second Law II
Experiment 9: Conservation of Energy