river

  1. H

    boat moving in a river

    I am looking for an explanation on how to calculate this situation. You are floating in a boat in calm water some distance D miles from a dam. A gate is opened at time T. You know the width and depth of the river, the size of the gate and how far above the low side of the dam it is located...
  2. E

    Calculate the time it takes for river gravel to take on the same temperature as the a

    Heres the scenario: Water level drops in a river. The previously saturated gravel slowly takes on the same temperature as the air. Assuming the gravel was originally the same temperature as the water, and the surface is flat, How long does it take? I believe these are the relevant formulas...
  3. M

    How to find the direction of the velocity of a man swimming across a river

    I am confused on the direction of the velocity of a man with respect to the river and with respect to the ground. Here is the question below: Question: A man can swim in still water at a speed of 3 km/h. He wants to cross a river that flows at 2 km/h and reach the point directly opposite to...
  4. D

    total mecanical energy of the river

    just need some help understanding one term in my equation I have taken a screen shot of the answers and question and posted the link to it below and highlighted the term I don’t understand the answers says you can ignore the kinetic and potential energy of the flowing river of height 90m and...
  5. M

    Boat Crossing River problems

    A boat wants to cross a 32.0m wide river from South to North. The current in the river is moving at 4.1m/s[west]. The station on the other side of the river is located 142m downstream from the original place. The boat's maximum engine speed(The boat's speed relative to water) is 6.0 m/s 1) At...
  6. C

    Jumping a river

    A physics professor did daredevil stunts in his spare time. His last stunt was an attempt to jump across a river on a motorcycle. the takeoff ramp was inclined at 53(degrees) the river was 40m wide, and the far bank was 15 m lower than the top of the ramp. The river itself was 100m below the...
  7. M

    [SOLVED] Swimming across a river

    A swimmer wants to cross a river, swimming directly from point A to point B, as shown in the figure. The distance d1 (from A to C) is 179 m, the distance d2 (from C to B) is 137 m, and the speed V_r of the current in the river is 5.00 km/h. Suppose that the swimmer's velocity relative to the...
  8. C

    A powerplant near a river- entropy question

    Hi, I am stuck on Termodynamics again (and I have an exam really soon)! A typical coal-fired power plant generates 1000 MW of usable power at an overall thermal efficiency of 40%. 1. The river's temperature is 18.0 degrees celcius before it reaches the power plant and 18.6 degrees...
  9. L

    velocity question - Jeep jumping river

    a bridge that was 15.0 m long has been washed out by the rain several days ago. how fast must a jeep be going to successfully jump the stream? although the road is level on both sides of the brdige, the road onthe far side is 2.0m lower than the road on the near side.