What are two radioactive isotopes that are useful for dating rocks that are older than 10 million years ?

The position of a dragonfly that is flying parallel to the ground is given as a function of time by r⃗ =[2.90m+(0.0900m/s2)t2]i^− (0.0150m/s3)t3j^. a: at what value of t does the velocity vector of the insect make an angle of 34.0 degree clockwise from the x-axis? b: at the time calculated in part (a), what is the magnitude of the acceleration vector of the insect? c : at the time calculated in part (a), what is the direction of the acceleration vector of the insect?

The government has declared that a hurricane is likely to hit the east coast. which government division is part of acf and provides guidance to citizens? a. job opportunities for low-income individuals b. office of human services emergency preparedness and response c. assets for independence d. low-income home energy assistance program

Consider an insulating crystal, made up of layers of atoms. what form would you expect the temperature dependence of the phonon heat capacity to approach at extremely low temperatures if the interlayer coupling is i)very strong (rigid coupling), and ii) very weak. explain.