Can you

1) this type of dating would be used to identify a frozen woolly mammoth
a) uranium-lead
b) potassium-argon
c)radiocarbon
d)rubidium strontium

2) petrified wood is an example of a placement remain
a) true
b) false

3) most index fossils are still living
a) true
b)false

In a stagnant pool of water, a crayfish may spend much of its time lying with one side of its carapace near the surface of the water. in this position, it will move the walking legs on that side in a rhythmic back-and-forth motion. explain the likely function of this behavior.

Need only answer if you think you know it

Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?