Is It Necessary for Capitalists to Be Producing?

In the capitalist mode of production, there is a removal between one's own subsistence and their own capacities. So they need to go through the mediating factor of earning money which they could then spend in the market so that they could live. One industry takes 52 weeks to actually sell their product and to earn their money back. For another another industry, it happens once every two weeks, happens 26 times a year. But mark says that the rate of exploitation is different between these two industries. He calls it a hundred dollars in cost, over a thousand hours of exploitation of that whole period. And i find that hard to swallow, and i generally have a difficult time understanding how ivetails with