It shows the doer of the action.It comes before verb and indicates this action or work is done by it/him/her etc.Ex.Susan switched off the lights. Who switched off the lights? The answer is Susan (subject of the sentence)
I'm not sure, I'd go for hushed in awe or your answer
Name an example of wedge. screw. inclined plane. lever. pulley. wheel and axle.
door stop. drill bit. truck loading ramp. nut cracker. crane. door knob.