In the US, under current law, this is probably illegal in every state, though I'm not positive about that. The usual cutoff age for riding in the front seat is 12.
A 9 year old child can ride in the front seat of a car. It is important that they are buckled in and can sit still.
no
order then a 10 year old
Yes, but if there is a air bag it has to be turned off and the child must be in a booster seat.
There is no law stating that a child has to ride in the rear seat of a vehicle. For safety reasons, it is better for a child to ride in the rear seat due to the fact of many recorded deaths involving children and airbags.
In the UK yes, but if they are under 140 centimetres tall, they are required to use a booster seat/child seat. (But that goes for the back of the car, as well as the front).
No
yes
no 12 and up yes
Yes
If their 80lbs or higher then yeah
If you consult the buckleupnc.org website, the recommendation is to keep your child in the back seat as long as possible. Children under 5 should always be in the backseat...but then it gets a little fuzzy. The recommendation is that children 1-12 should sit in rear seats whenever possible. My understanding is that once your child is age 12, they are usually tall enough to withstand the effect of an airbag deploying at 150-200 mph. FYI, over half the deaths caused by airbag deployment have been in children sitting in the front passenger seat.