There are two cities on a riverbank at distance x. On a day when water is still a steamer travels up and down in time `t_(1)` and when there is current of constant speed the steamer travels up and down in time `t_(2)` then

When the speed remains constant, the distance travelled is ______proportional to the time

Write down the relation between speed, distance travelled by the body and time taken.

From the top of a tower a stone is thrown up which reaches the ground in a time t_(1) . A second stone thrown down with same speed reaches the ground in a time t_(2) . A third stone released from rest from the same location reaches the gound in a time t_(3) . then

A boat takes 4 hrs to travel certain distance in a river in down stream and it takes 6 hrs to travel the same distance in upstream. Then the time taken by the boat to travel the same distance in still water is