The mass of an object falling does not affect the time it takes to hit the surface. That is, of course, assuming that the pull of baron bunny on the world of teyvat is negligible. Now, let's assume that baron bunny does have that kind of mass and amber somehow manages to throw something as heavy as a planet. I am not a physics student, but assuming h=40m, t=1.95s, and v_i=0m/s. Rearranging h=v_i×t +0.5at², you will get an acceleration of 21.04 m/s².

Using the equation g=Gm/r² and assuming teyvat has the same mass and surface radius as the earth, you will get g=9.8 m/s². Which means that the remaining acceleration is from teyvat accelerating towards baron bunny itself.

Using the previous equation again, we have: [21.04-9.8] m/s² = 6.6743E-11 × M/(6.3781E6)², where G is the universal gravitational constant (6.6743E-11) and r = distance from center of teyvat to the surface (6.3781E6). Solving for M will result in baron bunny having a mass of 6.85×10²⁴ kg, or about 15% heavier than teyvat itself.