Post on 06-Feb-2016
description
Atwood Machine
Atwood Machine
100 kg 100 kg
Would this move?
Atwood Machine
200 kg
100 kg
Would this move?
Which way?
Forces?
Fg = w
Fg = w
FTFT
Let’s break this up and analyze each mass…
200 kg
100 kg
Fg = w
Fg = w
FTFT
a
Compare the tension force now to when it’s not moving?
TENSION IS LESS
ΣF = 0 vs. ΣF = ma
200 kg
100 kg
Fg = w
FTFT
a
Compare the tension force now to when it’s not moving?
TENSION IS MORE
ΣF = 0 vs. ΣF = ma
200 kg
100 kg
Fg = w
Fg = w
FTFT
ΣF200 = -m200a
ΣF200 = FT – m200g
- m200a = FT – m200g
ΣF100 = m100a
ΣF100 = FT – m100g
-m200a = m100a + m100g – m200g
FT = m100a + m100g
m100a = FT – m100g
JOIN
-m200a = m100a + m100g – m100g
a = 10 m/s2 (-100kg + 200kg) (200kg + 100kg)
= 3.3 m/s2
- m100a- m100a
- m200a - m100a = m100g – m200g
+ m200a + m100a = - m100g + m200g
a (m200 + m100) = - m100g + m200g
(m200 + m100) (m200 + m100)
a = g (-m100 + m200) (m200 + m100)
a = 1000N 300kg
FT = m100a + m100g
FT = 100kg (3.3m/s2) + 100kg (10m/s2)
FT = 330 N + 1000 N
FT = 1330 N
1000 kg
500 kg
Which way would this move?
Forces?
Atwood Machine –Try this one…
Fg = w
Fg = w
FTFTFind the acceleration.