physics

A boat propelled so as to travel with a speed of 0.50m/s in still water, moves directly (in a straight line) across a river that is 60m wide. The river flows with a speed of 0.30m/s. How long in seconds does it take the boat to cross the river?

  1. 👍
  2. 👎
  3. 👁
  1. Presumably the boat is aimed perpendicular to the parallel banks, but the current carries it downstream.

    Just for orientation, let's say the river flows east, and the boat crosses to the north.

    In that case, we can draw a diagram involving the relative velocities. The boat's speed is .5 at 90 deg.

    The river's speed is .3 at 0 deg

    So, the boat's resultant speed is sqrt(.5^2 + .3^2) = .583 at 59.1 deg

    At that direction, the distance travelled is 60 sec 30.9 deg = 70m

    70m/.583s = 2 minutes

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics

    A boat propelled so as to travel with a speed of 0.5m/s in still water, moves directly (in a straight line) across a river that is 60m wide. The river flows with a speed of 0.30m/s. How long in seconds does it take the boat to

  2. phys science

    1. speed is the ratio of the distance an object moves to a. the amount of time needed to travel the distance** b. the direction the object moves c. the displacement of an object d. the motion of the object 2. a car traveled 60 km

  3. physics

    A boat moves through the water with two forces acting on it. One is a 2100. N forward push by the water on the propeller, and the other is a 1600. N resistive force due to the water around the bow. (a) What is the acceleration of

  4. PHYSICS

    A stone propelled from a catapult with a speed of 50m/s attains a height of 100m.Calculate:(a)the time of flight?

  1. math

    The speed of a river current is 4 mph. IF a boat travels 20 miles downstream in the same time that it takes to travel 10 miles upstream, find the speed of the boat in still water.

  2. Science

    A boat moves at a speed of 15 km/h in still water. The river it is traveling in flows at a rate of 3 km/h downstream. What is the velocity of the boat if it travels downstream? What is the velocity of the boat if it travels

  3. Math: Calculus - Vectors

    A boat travels at a speed of 5 m/s in still water. The boat moves directly across a river that is 70m wide. The water in the river flows at a speed of 2 m/s. How long does it take the boat to cross the river? In what direction is

  4. physics

    A stone propelled from a catapult with a speed of 50m/s attains a height of 100m. calculate: a.the time of flight b.the angle of projection c.the range attained:

  1. physics

    A boat can travel at a speed of 8km/h in still water on a lake.In flowing water of a stream, it can move at 8km/h relative to the water in the stream.If the stream speed is 3km/h, how fast can the boat travel upstream and

  2. cpcc

    Two people are pulling a boat through the water as in Figure P4.20. Each exerts a force of 600 N directed at a θ = 45.0° angle relative to the forward motion of the boat. If the boat moves with constant velocity, find the

  3. Pre AP-science

    A boy of mass 60 kg stands on a boat of mass 250 kg. This system is stationary. From the boat, the boy throws a rock of mass 1 kg into the water with a velocity of 10 m/s. What is the magnitude and direction of the boat's motion

  4. math

    a boat took 5 hours to travel 60 km up a river, against the current. the return trip took 3 hours. find the speed of the boat in still water and the speed of the current. if possible, show your steps

You can view more similar questions or ask a new question.