How much will a 3kg hammer exert on a nail if the hammer was swung at 25 m/s and the hammer comes to rest after a 0.08 second collision with the nail?

The gun from the crime scene shows tool marks where the serial numbers are ground off. there are also tool marks on the bullets left behind. what information can the tool marks on the bullets and gun provide about the crime? what type of evidence does this information provide, individual or class?