At a track meet, three different timers report the times for the winner of a 100-m sprint as 10.55 s, 10.47 s, and 10.38 s. The average is 10.47 s. How would you report the time of the sprinter in a way that reflects the uncertainty of the measurements

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 two required components for a generator are

What is the measurement of how fast an object moves relative to a reference point?