A fisherman moves from one end of a boat to another

Why is the use of carbon-14 limited

The direction of the current in an alternating current circuit remains constant. is direct. changes repeatedly. changes randomly.

Aturntable that spins at a constant 74.0 rpm takes 3.10 s to reach this angular speed after it is turned on. find its angular acceleration (in rad/s2), assuming it to be constant, and the number of degrees it turns through while speeding up.