What is flow rate？

What is flow rate? What letter is it expressed as? How many measurement units are there? How to convert different measurement units? How to convert it into weight and what is the formula?

The flow rate is the volume of the liquid that the pump discharges in unit time. The flow rate is expresses as Q, the measurement unit: cubic meter/ hour (m3/h), liter/ seconds (l/s)
L/s=3.6 m3/h=0.06 m3/min=60L/min   G=Qρ G is weight and ρ is specific gravity of liquid

 Example: The flow rate of a pump is 50m3/h. Please figure out the weight per hour when drawing water? Note: the specific gravity of water is 1000 kilograms/ cubic meters
Solution: G=Qρ=50×1000(m3/h•kg/ m3)=50000kg / h=50t/h