How to hammer a nail into a rock ceiling using a hammer without making the nail bend after hitting.

1. Choose a nail that is strong and sturdy enough to penetrate the rock ceiling without bending. A nail made of hardened steel or titanium would be ideal for this task.

2. Hold the nail firmly in place on the rock ceiling where you want to drive it in. Make sure the nail is positioned straight and perpendicular to the surface of the rock.

3. Use a hammer with a heavy head and a comfortable grip to strike the nail. Hold the hammer firmly and position it directly above the nail.

4. Begin striking the nail with controlled and consistent force. Start with light taps to create a small indentation in the rock, then gradually increase the force of your strikes to drive the nail deeper.

5. Make sure to strike the nail squarely and avoid hitting it at an angle, as this can cause it to bend. Aim for the center of the nail head with each strike to ensure that the force is evenly distributed.

6. Continue driving the nail into the rock ceiling until it is securely in place. If you encounter resistance or the nail starts to bend, stop hammering and reposition the nail before continuing.

7. Once the nail is fully driven into the rock, check to ensure that it is secure and not at risk of coming loose. If necessary, use additional nails or anchors to reinforce the attachment.

It is not possible to hammer a nail into a rock ceiling without damaging the nail. Rock is a very hard material, and nails are not designed to be driven into hard materials. Attempting to do so will likely bend or break the nail.