Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
Time to cross an 800 m river: depends only on \vec v_b * \hat\jmath = 4 km/h. (Ans: 12 min.)
Time to cross an 800 m river: depends only on \vec v_b * \hat\jmath = 4 km/h. (Ans: 12 min.)
Natural Language
Math Input
Extended Keyboard