Acceleration on an inclined plane

[ANGLA]

Homework Statement

The question says "A block of mass 4kg on a friction less inclined plane at angle of 30° is connected by a cord over massless friction less pulley to a second block of mass 2.3kg hanging vertically. What is the magnitude of acceleration of each block."

Given
m1 = 4 kg
m2 = 2.3 kg
teta = 30°
g = 10 m/s*s(second square)

Required
a1 = ?
a2 = ?

Homework Equations

m1*a1 = m1gsin(teta)

The Attempt at a Solution

I drived the equation "a1 = gsin(teta)"

So a1 = 10m/s(square) * sin (30°)
a1 = 5 m/s(square)

For a2 i used 90° as the angle since it was vertical it creates a ninety degree.

So a2 = 10m/s(square) * sin90° = 10 m/s(square).

Please help me... i don't have any idea

 

[Doc Al]

m1*a1 = m1gsin(teta)

That would be true if the only force on the sliding block was gravity. But there's a cord attached to it!

Draw Free Body Diagrams for each mass, identifying the forces that act on each.

 

[Hen Sharir]

since the 2 masses are connected they should have the same acceleration

 

[hilbert2]

Find the sum of the two forces (they are of different signs) and presume that they are acting on a single object with mass $m_1 + m_2$. That way you get the acceleration which is same for both objects when the cord is unstretchable.