What is the magnitude of the acceleration of the masses?

Two masses are connected by a weightless cord, which passes over a frictionless pulley. The masses are held stationary and then released. The acceleration due to gravity is g.enter image source here

2 Answers
Jan 13, 2018

g/4

Explanation:

For mass m_1

T-m_1 g = m_1 a_1

for mass #m_ 23

T-m_2 g = m_2 a_2

assuming the weightless cord is inextensible

a_1 = -a_2 = a then

a = ((m_2-m_1)/(m_1+m_2))g = 1/4 g

Jan 13, 2018

g/4 (m/s^2) for 5 kg it's downwards and for 3 kg it's upwards

Explanation:

Clearly the 5 kg will go downwards and as a result the cord will try to pull the 3 kg above.
Let tension in cord is T
So,for 5 kg we can write,
5g-T = 5a ..1( a is the acceleration of the system)
For, 3 kg we can write,
T- 3g = 3a ..2
Eliminating T from both we get, a= (5g-3g)/(5+3) m/(s^2)
I.e g/4 m/(s^2)