Your company develops radioactive isotopes for medical applications. In your work there, you measure the activity of a radioactive sample. Your results are given in the table. Time (h) Decays,s 0 20,000 0.5 14,800 1.0 11,000 1.5 8130 2.0 6020 2.5 4460 3.0 3300 4.0 1810 5.0 1000 6.0 550 7.0 300 (a) Find the half-life of the sample. (b) How many radioactive nuclei were present in the sample at t = 0? (c) How many were present after 7.0 h?

Lecture 3 VECTORS In 1 dimension, we use + or – to indicate direction of a vector In 2 or 3D we need more than just a sign to indicate direction, such as an angle We express vectors as arrows, there the tail of the arrow is where the vector starts and the tip is where it ends. The length of the arrow represents...