Where does the bulk of atmosphere oxygen come from

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?

In physics the desire of an object to keep doing what it is doing is termed?

If 21.2 kcals of energy is released by this reaction, how many kj does the reaction release? (1 cal 4.184 j)