At 2.5 seconds, the helicopter has a kinetic energy of 20 j. what is it mechanical energy at that time?

The mechanical energy of an object is equivalent to the sum of its potential and kinetic energy. If the helicopter is grounded, then its mechanical energy will be 20 J. If it is in the air, then its potential energy will be calculated using:
P.E = mgh
And then added to the kinetic energy to obtain mechanical energy.

Some of her  assignments would be creation of drugs. she is a medical chemist after all so she'd need to have the necessary knowledge to make medicine which can later be sold in a pharmacy