If the labor force is cut to 940 worker-hours, the factory will produce 12248 fewer units per day.
Estimating the effect on output if the labor force is cut
From the question, we have the following parameters that can be used in our computation:

When there are 1000 worker hours of labor, we have

Evaluate
Q(1000)} = 600000
If the labor force is cut to 940 worker-hours, we have the output to be

Evaluate
Q(940) = 587752
So, we have
Reduction = 600000 - 587752
Reduction = 12248
Hence, the estimated effect on output is a reduction by 12248 units per day