I'm guessing from the "year X" comments that this is not in the United States. But I think what we do is probably helpful anyway. My daughter is in middle school (so, 6th grade, not sure how that translates for you). She has some nightly assignments (given in class, due the next day), some weekly assignments (given on Friday, due the following Friday) and some long-term assignments that take 3-4 weeks to complete. She trains 10 hours a week for gymnastics, performs musical theater periodically and sings in the school choir. We all participate in church activities. Both of us work full-time and I have a high-school aged son who also has a sport and music. Looking at that -- no wonder I'm always tired!
For us, organization and motivation are key. We have set times for homework - though it varies by day of the week due to activity schedule. We make a plan each Friday for the following week (Friday rather than Monday since some stuff must get done on the weekend). This includes a portion of long-term assignments. While I don't restrict TV, the rule is that that days plan must be finished before TV or computer (for fun) is turned on -- violation of this rule results in no electronics the following day. For weekly assignments she does as much on the weekends as possible. Right now there are meets every weekend, which makes it tough. We have found that she works best laying on the floor in the living room with headphones on with music. Drives me crazy but that's how she works best. My son works at his desk, alone and in silence. It was important to figure this out so everyone was working in an environment that worked for them. We do use car time for memorization practice -- be that multiplication tables (when she was younger), music or theater lines. Over the years both kids have learned that it is easiest if you sit down and do it quickly rather than draw it out. I think they finally got this after I kept pointing out to them how much easier it was and how much better the day was if they worked quickly. They both ride their bikes home from school, so that helps get them some physical exercise before they have to start homework, though 2 days a week she goes straight to gymnastics (the other 3 days are evening practices). For my son, when he was younger, it was crucial to divide things up, so he would do 30 minutes of homework and then have a 30 minute break where he could go out and play or whatever. He also needs a longer "wind down" time between school and homework. I think its important to figure out how your child works best and work around that.
In terms of the types of homework, it might be worth talking to the teacher. Not necessarily to ask for a change right up front, but to ask what the plan is for the year. It might be that a month from now the teacher plans a major switch from language arts to math. In my experience, everything generally balances out in the end but you should definitely ask about the overall plan for the year. Maybe this is a year that emphasizes language and next year will be a math/science focus? Probably depends a lot on local conditions.