Aboy throws a rock straight up into the air. it reaches the highest point of its flight after 2.5 seconds. how fast was the rock going when it left the boy's hand?

Explanation:

As we know that when rock moves upwards against gravity the velocity of rock will decrease with time and when it will reach the highest point it's velocity becomes zero

So we can use kinematics equation here such that

now we will have

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.