Download Newton`s Second Law Pre-Lab Day 1 (print

Newton’s Second Law Pre-Lab
Modified Atwood’s Machine
A
What variables affect the acceleration of an object?
D Acceleration
I Net Force 
B
FgB  mB g
I Mass
FN  FgA

FN

FgA
Angle of track?
B
A
Friction?

FgB
Mass of cart (A)
Hanging mass (B)
System
Mass
The track is tilted so that the cart
moves with constant velocity
when given a small push.
Newton’s Second Law Pre-Lab
Purpose: To create graphical and mathematical representations of the
relationship between the acceleration, the net force, and the
mass of a modified Atwood’s machine.
Mass can be measured with the electronic balances around the room.
To measure the acceleration you must use Data Studio and the motion detector to find
the slope of the velocity vs. time graph.
Newton’s Second Law
Newton’s Second Law Pre-Lab
Acceleration vs. Force with constant Mass
 Open the Data Studio file Newton’s Second Law.
 Add the following masses to the cart.
1 – black bar mass
=
kg
2 – 5 g masses
=
0.010 kg
2 – 20 g masses
=
0.040 kg
1 – 50 g mass
=
0.050 kg
3 – 100 g masses
=
0.300 kg
1 – 200 g mass
=
0.200 kg
Total mass in cart
=
kg
Newton’s Second Law Pre-Lab
Acceleration vs. Force with constant Mass
How can we change the force but keep the system mass constant?
A
B
 To keep the mass constant, all mass must now stay either on the
string or in the cart!
Move 40. g = 0.040 kg from the cart to the end of the string for the first trial.
 Don’t forget, the mass hanger adds 5 g = 0.005 kg to the hanging mass.