**Or**

**Option 2**

Upwards as positive:

Displacement from roof to meeting point: -40 + 29,74 = -10,26m.

Displacement of stone A from max height to meeting point: -15,36 m.

**Stone A**

^{(1)}

^{(2)}

**Stone B**

^{(3 + 4)}

^{(5 + 6)}

**Or**

^{(3 + 4)}

^{(5)}

^{(6)}

**Or**

Downwards as positive:

Displacement from roof to meeting point: 40 - 29,74 = 10,26m.

Displacement of stone A from max height to meeting point: 15,36 m.

**Stone A**

^{(1)}

^{(2)}

**Stone B**

^{(3)}

^{(4 + 5)}

**Or**

^{(3)}

^{(4 + 5)}

^{(6)}

**Or**

**Option 3**

Upwards as positive:

Displacement from roof to meeting point: -40 + 29,74 = -10,26m.

**Stone A**

^{(1)}

^{(2 + 3)}

**Stone B**

^{(4)}

^{(5 + 6)}

**Or**

^{(4)}

^{(5)}

^{(6)}

**Or**

Downwards as positive:

Displacement from roof to meeting point: 40 - 29,74 = 10,26m.

**Stone A**

^{(1)}

^{(2 + 3)}

**Stone B**

^{(4)}

^{(5 + 6)}

**Or**

^{(4)}

^{(5)}

^{(6)}

**Or**

**Option 4**

Upwards as positive:

Displacement from roof to meeting point: -40 + 29,74 = -10,26m.

**Stone A**

^{(1)}

^{(2 + 3)}

**Stone B**

^{(4)}

^{(5 + 6)}

**Or**

^{(4)}

^{(5)}

^{(6)}

**Or**

Downwards as positive:

Displacement from roof to meeting point: 40 - 29,74 = 10,26m.

**Stone A**

^{(1)}

^{(2 + 3)}

**Stone B**

^{(4)}

^{(5 + 6)}

**Or**

^{(4)}

^{(5)}

^{(6)}

**Or**

**Option 5**

Upwards as positive:

Displacement from roof to meeting point: -40 + 29,74 = -10,26m.

Displacement of stone A from max height to meeting point: -15,36 m.

**Stone A**

^{(1)}

^{(2)}

**Stone B**

^{(3 + 4)}

^{(5 + 6)}

**Or**

^{(3)}

^{(4 + 5)}

^{(6)}

**Or**

Downwards as positive:

Displacement from roof to meeting point: 40 - 29,74 = 10,26m.

Displacement of stone A from max height to meeting point: 15,36 m.

**Stone A**

^{(1)}

^{(2)}

**Stone B**

^{(3 + 4)}

^{(5 + 6)}

**Or**

^{(3)}

^{(4 + 5)}

^{(6)}

**Or**

**Option 6**

Upwards as positive:

Displacement from roof to meeting point: -40 + 29,74 = -10,26m.

**Stone A**

^{(1)}

^{(2)}

**Stone B**

^{(3 + 4)}

^{(5 + 6)}

**Or**

^{(3)}

^{(4 + 5)}

^{(6)}

**Or**

Downwards as positive:

Displacement from roof to meeting point: 40 - 29,74 = 10,26m.

**Stone A**

^{(1)}

^{(2)}

**Stone B**

^{(3 + 4)}

^{(5 + 6)}

**Or**

^{(3)}

^{(4 + 5)}

^{(6)}