What are atoms that have the ability to spontaneously continuously decay

In automobile steering wheel is shown what is the ideal mechanical advantage blank? if the ama is eight what is the efficiency of the steering wheel?

A4.0-cm tall light bulb is placed a distance of 32.0 cm from a concave mirror having a focal length of 16.0 cm. determine the image distance

Farmer a has a deep well and needs a lot of water for her animals and crops. her neighbor, farmer b, has a shallower well. he needs less water than farmer a because his farm is smaller. in years of drought, sometimes farmer b can't get any water from his wells. what can farmer b do to decrease the likelihood of his well running dry?