physics

A boat travels at 3.8 m/s and heads straight across a river 240 m wide. The river flows at 1.6 m/s. Find
A) The boat's resultant velocity.

B) How long it takes the boat to cross the river.

C) How far downstream the boat is when it reaches the other side.


Please help, i have about 12 of these problems that I understand NONE of.

  1. 👍 0
  2. 👎 0
  3. 👁 191
  1. The time it takes to get across is 240m divided by 3.8 m/s, which is 63.2 seconds. In that time the current has moved boat downstream by: 1.6 m times 63.2 seconds, or 101.1 meters. Then to get the resultant velocity, you need to add the velocity vectors. Use pythagorean theorem: resultant^2 = 3.8^2 + 1.6^2. The resultant velocity is 4.1 m/s. Does this make sense??

    1. 👍 0
    2. 👎 0
    posted by DanH
  2. Lazy Laz

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. physics - need help right now.

    A boat travels at 3.8 m/s and heads straight across a river 240m wide at an angle of 145'. The river flows at 1.6 m/s. a. What is the boat's resultant speed with respect to the river bank? b. How long does ti take the boat to

    asked by joshua on October 18, 2009
  2. Physics

    A boat travels at 3.8 m/s and heads straight across a river 240m wide at an angle of 145'. The river flows at 1.6 m/s. a. What is the boat's resultant speed with respect to the river bank? b. How long does ti take the boat to

    asked by joshua on October 19, 2009
  3. Physics - URGENT

    A boat travels at 3.8 m/s and heads straight across a river 240m wide at an angle of 145'. The river flows at 1.6 m/s. a. What is the boat's resultant speed with respect to the river bank? b. How long does ti take the boat to

    asked by joshua on October 19, 2009
  4. Physics

    A boat travels at 3.8 m/s and heads straight across a river 240m wide at an angle of 145'. The river flows at 1.6 m/s. a. What is the boat's resultant speed with respect to the river bank? b. How long does ti take the boat to

    asked by joshua on October 18, 2009
  5. Physics

    A boat travels at 3.8 m/s and heads straight across a river 240m wide at an angle of 145'. The river flows at 1.6 m/s. a. What is the boat's resultant speed with respect to the river bank? b. How long does ti take the boat to

    asked by joshua on October 18, 2009
  6. Physics

    A boat travels at 8m/sec and heads straight across a river 240m wide. The river flows at 4m/sec. What is the boats resultant speed with respect to the riverbank

    asked by Tori on October 26, 2015
  7. PHYSICS. HELP.

    A motorboat heads due west at 10 m/s. The river has a current that travels south at 6 m/s. a) what is the resultant velocity? b) If the river is 200 m wide, how long doe sit take the boat to cross the river? c) How far downstream

    asked by Kiley on November 4, 2008
  8. Physics

    A current of a river flows steadily from west to east at 1.00 m/s. A boat in the river travels at 3.00 m/s relative to the water. The river is 20.0 m wide with parallel banks. The boat leaves the shore at point A, and point B is

    asked by . on September 19, 2010
  9. Physics

    A motorboat heads due east at 8.5 m/s across a river that flows to the south at a speed of 2.5 m/s. a. What is the velocity of the boat relative to a stationary observer on the shore? B. If the river is 1360 m wide, how long does

    asked by Lilah on January 4, 2011
  10. mechanics

    (b) A boat heads North at 2.4 ms-1 across a river that flows East at 1.6 ms-1. (6 marks each) (i) Calculate the resultant velocity of the boat. (ii) The river is 30 m wide. What is the displacement from the starting point when the

    asked by Kae on March 13, 2013

More Similar Questions