Given that the acceleration vector is a(t)=(−9cos(−3t),−9sin(−3t),−t), the initial velocity is v(0)=(1,0,1), and the initial position vector is r(0)=(1,1,1), compute:

It is d, all the other ones say incorrect answer .

The magnets are probably damaged or there not strong enough to attached to the refrigerator

Molybdeum(mo)orruthenium (ru)actually, elements with similar chemical properties as technetium would bemn, re, and bh. this is because elements in the same group/family (column) have similar chemical properties. elements in the same period (row) have the same number of energy levels (or shells).