Based on the principles of convection, conduction and thermal radiation, which scenario below is most similar to the following situation? You put a heating pad on your back after exercising.
Question 20 options:

Feeling a metal wire get warmer as you roast a marshmallow over a fire.

Warm air rising in a room where the air is moving.

The sun warming up the roof on a house.

Cold water sinking in a pot of water being warmed up on the stove.
Question 21 (1 point)

An engine, weighing 3000 n, is supported on a pedestal mount. it has been observed that the engine induces vibration into the surrounding area through its pedestal at the maximum operating speed. determine the stiffness of the dynamic vibration absorber spring in (n/m) that will reduce the vibration when mounted on the pedestal. the magnitude of the exciting force is 250 n, and the amplitude of motion of the auxiliary mass is to be limited to 2 mm note: in this question type-in right numbers, no decimals, no fractions, no unit. approximate to right number if needed

List and describe in sequence the operation process steps for boxf machine?

Different between right hand turning tool and left hand turning tool ?