In which of the following cases is work being done on an object? question 2 options: pulling a trailer up a hill carrying a box down a corridor suspending a heavy weight with a strong chain pushing against a locked door

Work is done when a force acts on an object AND the object moves in the direction of the force.

-- Pulling a trailer up a hill.  YES. The trailer is moving in the direction of the pulling force.  

-- Carrying a box down a corridor.  No. The box is not moving in the direction of gravity (down) OR in the direction of your arm (down the corridor).

-- Suspending a heavy weight with a strong chain,  No.  There's a force (gravity) acting on the weight, but the weight is not moving at all.

-- Pushing against a locked door.  No.  There's a force (your muscles) acting on the door, but he door is not moving at all.

  the unit of the measure =

explanation:

  the property that is quantified by the energy needed per of material to raise the temperature by one.

  si unit of energy = joule (j)

  si unit of temperature = kelvin (k)

  si unit of mass of material = kilogram (kg)

the property that is quantified by the energy needed per of material to raise the temperature by one is called specific heat.

the unit of specific heat is

it would be c. predictability