A small wooden block with mass 0.850 kg is suspended from the lower end of a light cord that is 1.54 m long. The block is initially at rest. A bullet with mass 0.0104 kg is fired at the block with a horizontal velocity v(initial. The bullet strikes the block and becomes embedded in it. After the collision the combined object swings on the end of the cord. When the block has risen a vertical height of 0.800 m, the tension in the cord is 4.72 N.
What is the initial speed of the bullet?