Hi when i'm trying to solve, i get the following warning: Warning, solutions may have been lost.

The equations i'm trying to solve are the following:

> P := 21000;

> v := 10/(60*1000);

> r := 983;

> Cp := 4181;

> Tl := 40;

> K1 := 124.27;

> K2 := 102.03;

> K3 := 7.23;

> K4 := 2.947;

> eqn1 := P = v*Cp*r*(Tf-Tr);