Iron-59 is used in medicine to diagnose blood circulation disorders. The half-life of Iron-59 is 44.5 days. A 2mg sample is injected into a patient. How long would it take for the sample to decay until only 0.25mg is left in the patient?

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e

The sun’s mass is 2.0×10^ 30 kg, its radius is 7.0×10 5 km, and it has a rotational period of approximately 28 days. if the sun should collapse into a white dwarf of radius 3.5×10 3 km, what would its period be if no mass were ejected and a sphere of uniform density can model the sun both before and after?

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up