speed

  1. M

    Average Speed of Ship

    One knot is 1 nautical mph, and 1 nautical mile is 6080 feet. If a cruiser ship has an average speed of 3.5 knots, what is the average speed, in mph, of the ship? Also, is there an average speed formula?
  2. J

    ...speed

    Two towns are 165 km apart. A car and a bus start travelling towards each other from their respective towns. The car moves 10 km/h faster than the bus. If they pass each other in 1.5 hours after they began their respective journeys, find the speed of each vehicle. I'm guessing I have to use...
  3. M

    Differentiation(average speed)

    I'm not sure about this so a bit of help would be great. Determine the average speed given that the distance travelled, s, in metres, relative to time, t, in seconds is s(t)=2t^2 + 1, between t=2 and t=4 Do I first do the first derivative of s(t)=2t^2 + 1 to get the equation for the speed at a...
  4. S

    Vector question (relative speed)

    A plane goes from city A to city B. In a Cartesian plane, city A is at the origin and city B has coordinates (100,150). If there is no wind, the flight lasts one hour. Unfortunately, there is a wind. If the pilot does not adjust his flight path, he will be at point (120,160) after an hour. What...
  5. M

    Train's Average Speed

    A cattle train left Miami and traveled toward New York. 14 hours later a diesel train left traveling at 45 km/h in an effort to catch up to the cattle train. After traveling for four hours the diesel train finally caught up. What was the speed of the cattle train’s average speed?
  6. D

    Did I answer this correctly? Trig rotation question

    A car is traveling at 50 mph. Find the revolutions per minute of the wheels if the car tires have a 26 inch diameter. 50 mph , 13 inch radius 50 mph(5280ft in a mile)/60 min an hour = 4400 ft/min total distance in 1 minute ---------------^ 13 inches/12 inches in a foot * 2pi = 13pi/6...
  7. I

    speed problem?

    A train starts from station A and accelerates and attains a velocity of 72kmph, it gets decelerated because it travelled through 1 km of being repaired track, it's speed becomes 18kmph, after crossing this track it attains original velocity and moces on, then, to reach station B it has to...
  8. M

    Find Average Rate of Speed

    Maryann drove 280 miles to attend a marine biologist conference and arrived 1 hour late. Maryann figured out that, had she increased her average speed by 5 mph, she would have arrived on time. What was her average rate of speed? Isn't the average rate found using r = D/t?
  9. M

    Average Speed

    Lenore drove 200km. For the first 100km of the trip, she drove at a speed of 40 km/h. For the second half of the trip, she traveled at a speed of 60 km/h. What was the average speed of the entire trip? MY WORK: I know we can use R = D/t I first need to find the time. T = D/R T =...
  10. P

    Speed Time Distance Word Problem

    Hi, first time poster here! I really need some help with this word problem. A ferry goes between two ports that are 24 km apart. One day the ferry begins the trip 6 minutes late. In order to reach the other port at the correct time, it goes 8 km/h faster than usual. What is the ferry's normal...
  11. H

    Speed of convergence

    Hi guys, I'm a little confused by the terminology "speed of convergence", particularly as applied to proving the irrationality of a number. What does it mean that one sequence converges "faster" than another? Specifically, in the use of the criterion for irrationality, namely, If there is a...
  12. D

    [SOLVED] linear/angular speed (another question)

    "suppose that a belt drives two wheels of radii R (bigger wheel) and r" there is a figure and it's like a big wheel and a small wheel with a belt around them.....so they have the same linear speed i think... R=8 ft r=3 ft a) the angular speed of the larger wheel in radians/minute - i...
  13. D

    [SOLVED] linear/angular speed?

    If a rocket car with 20 inch radius tires brakes the sound barrier (a speed in excess of 760 miles/hour), what is the angular speed of the wheels in revolutions/second? ok i am totally lost.....all i know is one revolution would probably be 40pi inches because that the circumfrence of the...
  14. P

    Speed Problem

    Train Speed. A freight train requires 2.5 hours longer to make a 300-mile journey than an express train does. If the express averages 20 mph faster than the freight train, how long does it take the express train to make the trip? This problem is different than any of the other speed/distance...
  15. L

    [SOLVED] Finding the speed from the velocity

    ok so the veloctiy is: v(t) = (-2sint)i + (3cost)j +4k so to find the speed you do squareroot((-2sint)^2 + (3cost)^2 +(4k)^2) = squareroot(4sin^2t + 9cos^2t + 16k^2) the book says the speed is 2 * squaroot(5) i have no idea how to get that from where i left it off.
  16. L

    Trucks speed...

    A truck is accelerating over a certain distance (in metres). Its final speed (v m/s) is related to its starting speed (u m/s), according to the rule v²=u²+1500. Find the truck's starting and final speeds, given that the truck's final speed is 5 times its starting speed.
  17. S

    grade 10 word problems (speed, time, distance)

    question: An airplane has a speed of 250km/hour. One day it flies 990 kms with a tailwind, and then returns against the wind. The total trip-time is 8 hours. Find the velocity of the wind (assume it is constant). I honestly just completely dont get this question, i dont find that the wind speed...