1. **State the problem:** A sample of tin absorbs a total of 1050 J of heat. Out of this, 460 J is used to raise the temperature to the melting point. We need to find how much heat is required to completely melt the tin sample. 2. **Identify the formula and concepts:** The total heat absorbed ($Q_{total}$) is the sum of the heat required to raise the temperature to the melting point ($Q_{heat}$) and the heat required to melt the sample ($Q_{melt}$): $$Q_{total} = Q_{heat} + Q_{melt}$$ 3. **Substitute the known values:** $$1050 = 460 + Q_{melt}$$ 4. **Solve for $Q_{melt}$:** $$Q_{melt} = 1050 - 460$$ $$Q_{melt} = 590$$ 5. **Interpretation:** The heat needed to completely melt the sample of tin is 590 J. **Final answer:** $$\boxed{590\text{ J}}$$