CBSE Class 11-science Answered
well its not so complicated, here we shall use the concept that the time taken by pacakage to travell vertical distance is equal to the time taken by the boat to just reach beneath the bridge.
Now time taken by the pacakage can be calculate by applying equation of motion
here initial velocity is zero, so h=(1/2)gt2 from here we can calculate the time taken by the package.
now till the package reaches just beneath the bridge, then boat will arrive there
so we can calculate the time taken by the package from above equation.
then distance travelled by the boat we can calculate as distance= speed multiply by time. and the value of time can be calculated from the above equation.
i hope you understood.