Assign the proper sign to q and w in the following cases :
30 kJ of energy is lost by the system on account of the work done by the system on the surroundings.

Explanation

To solve the problem of assigning proper signs to \( q \) (heat) and \( w \) (work) in the given scenario, we will follow these steps:

### Step 1: Understand the Context
The problem states that 30 kJ of energy is lost by the system due to work done by the system on the surroundings. This indicates that the system is losing energy.

### Step 2: Determine the Sign of \( q \)
In thermodynamics, the sign of \( q \) (heat) is defined as follows:
- \( q \) is positive when the system absorbs heat (endothermic process).
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