a man is using an axe to chop down a tree. After a short time after the axe hits with tree the man hears a clear echo he estimates that the echo is 3 seconds after the axe hits the tree. suggest what type of obstacle might have caused such a clear echo​

Agymnast dismounts off the uneven bars in a tuck position with a radius of 0.3m (assume she is a solid sphere) and an angular velocity of 2rev/s. during the dismount she stretches out into the straight position, with a length of 1.5m, (assume she is a uniform rod through the center) for her landing. the gymnast has a mass of 50kg. what is her angular velocity in the straight position?

Which is the best predictor of the radioactive nature of an isotope? o the proton-to-electron ratio the neutron-to-proton ratio o the neutron-to-electron ratio the electron-to-proton ratio

Ms. hidalgo opens the door to her classroom. her classroom is 60 degrees and the air outside is 80. predict what will happen using your knowledge of how heat flows.