PASCO ME-9502 Statics System - Manual (Page 90)

S t a t i c s S y s t e m E x p . 1 6 : M o d i f i e d A t w o o d ’ s M a c h i n e
®
86 012-12876B
Setup
1. Place the two Small Pulleys on the Statics Board near
the top edge of the board and close to each other.
Make sure that the two pulleys are level.
2. Connect a thread from one Mass Hanger to a second
Mass Hanger so the hangers are suspended over the
two pulleys.
• NOTE: Make the thread long enough so that the heavy
mass almost reaches the base of the Statics Board
when the light mass is almost up to the pulley.
3. Pull the M
1
mass hanger down so that the top of the
M
2
mass hanger is just below the base of the pulley.
Use a dry-erase marker or a pencil to put a horizontal
mark on the Statics Board for the position of the bottom edge of the M
2
mass hanger.
4. Measure vertically down from the first mark a distance of 20 cm (0.020 m) and put a second horizontal mark
on the board.
Procedure
Part 1: Keep Total Mass Constant
1. Put the following on the ‘light’ (M
1
) mass hanger: 1 x 50-g, 3 x 20-g, 2 x 5-g, 2 x 2-g, 1 x 1-g. Put the follow-
ing on the ‘heavy’ (M
2
) mass hanger: 1 x 50-g, 3 x 20-g, 1 x 10-g, 1 x 5-g.
2. Including each 5-g mass hanger, record the total mass for M
1
and the total mass for M
2
in the Data Table.
3. Move the 1-g mass from the light mass hanger to the heavy mass hanger (so the difference in mass is 1 g). Pull
the light mass hanger down so that the bottom edge of the heavy mass hanger is aligned with the starting mark
on the Statics Board.
• NOTE: Stop the hangers from spinning or swinging.
4. Release the light mass hanger and start timing at the same instant. Stop timing when the bottom edge of the
heavy mass hanger reaches the finish mark on the Statics Board. Record the time, t
1
, in the Data Table. Repeat
the trial two more times and record the results.
5. For the second trial, return the 1-g mass to the light hanger and move one of the 2-g masses to the heavy
hanger (
M = 2 g). Repeat the data recording procedure three times.
6. For the third trial, move the 1-g mass from the light hanger to the heavy hanger (
M = 3 g) and repeat the pro-
cedure three times.
7. For the fourth trial, move the 1-g mass from the heavy hanger back to the light hanger and move the 2-g mass
from the light hanger over to the heavy hanger (
M = 4 g) and repeat the procedure three times.
8. For the fifth trial, move the 1-g mass from the light hanger to the heavy hanger (
M = 5 g) and repeat the pro-
cedure three times.
Figure 16.2: Equipment Setup
Pulley
M
2
Thread
Mass
hanger
M
1
Mass
hanger
Pulley
Bottom edge of
mass hanger