What should the questioner do when the time for prayer arrives while he is working with his father in a place where there is no mosque, or if his father delays the prayer slightly and he is compelled to pray alone, or if he hears the adhan in the car and his father does not stop, thus causing him to miss the first congregational prayer?

If you hear the call to prayer from the mosque without a loudspeaker, you should go to pray there to attain the reward of congregational prayer and striving for it, because many jurists obligate praying in the mosque for anyone who hears the call.

If you are not within that distance, then you and your father should be keen to perform the prayer in congregation at the beginning of its time, based on the saying of the Prophet, peace and blessings be upon him: "Indeed, a man's prayer with another man is purer than his prayer alone." Many scholars hold the view that the obligation of congregational prayer is fulfilled by performing it, even if not in the mosque.

If your father delays the prayer beyond its preferred time, then pray alone at the beginning of the time. If he delays it until the very end of the preferred time, then you have the choice between praying alone at the beginning of the time or waiting to pray with him in congregation.

The questioner is advised to be keen on performing congregational prayer in the mosque as much as possible.