m1=100kg m2=1500kg m3=0,005kg f-?

To calculate the force (F), we need more information regarding the context of the problem. Force can be calculated using Newton's second law of motion, which states:

\[ F = m \cdot a \]

Where:

• \( F \) is the force applied,
• \( m \) is the mass,
• \( a \) is the acceleration.

If you can provide the acceleration or the specific scenario considering these masses (for example, if they are in a system where one mass is being moved by another), I can help you compute the force. Please provide additional details!