Which statement about how geologists study the ages of rock layers is true?

the law of superposition means that older rocks are on top.
geologists can find the exact age of a rock by looking at its relative position.
the principle of original horizontality provides the basis for the law of superposition.
relative age can be determined by using the concept of unconformity.

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?