1. MoniMini

    Average Speed

    Hi all, I did the conversions and used the formula ( avg. sp = (total d)/(total time) ) but I couldn't get close to anyone of the options. Thanks
  2. F

    Angular and Linear Speed.

    My prof posted this problem as an example and, going over the steps, I haven't been able to work out how he got to the final answer. A car has tires with 10 inch radius and is traveling at 60 miles per hour. Find the angular speed of the wheels in radians per second. (60 miles/hr) = (60...
  3. C

    Predicting Tartget Speed

    Hey - I have a Ball moving at a Speed S. - The Ball has an InitialSpeed iS - The Ball has a TargetSpeed tS Every second: - Ball is displaced S number of pixels - S is multiplied by deacceleration D ( D is a number between 0 - 1 ) ... I need an expression, returning how many pixels the Ball...
  4. R

    Equation for one speed relative to another

    If I have a car with a tyre diameter of 50cm and swap the tyres to a smaller diameter of 45cm (therefore affecting the speedometer accuracy), how could I determine an equation that relates the true speed with the display speed? I'm having trouble getting my head around this and any help is...
  5. C

    Discrete and continuous modelling

    Hi there, I am currently stuck on this question. A woman is running along the line x = 50 (assuming constant speed) Her dog returns a ball to her but runs in a curved line, as the dog runs towards wherever she is at any instant. To simplify the problem, we assume that the dog starts his...
  6. J

    Acceleration varying with speed problem

    Hi, I'm attempting to solve a problem where the torque of a motor varies with RPM linearly. I've done most of the groundwork, and come up with this equation for how acceleration would vary with the speed of the vehicle a = -1.2503v + 1.4533 From this and F = ma, I think I should come up with...
  7. M

    Speed question. please help

    My old Holden’s speedometer was not calibrated correctly it displayed70 km/h when its true speed was 55 km/h, it also displayed 40 km/h whenits true speed was 32 km/h. (a) Using the variables T for true speed and D for displayed speed, determine the linear equation that could relate the...
  8. L

    boat speed equation

    " if a boat is moving straight in a line, with speed = v, through water with a resistance which is proportional to v^2; with initial speed v_o and position x_o, find v(t) and x(t)"
  9. L

    Determining the speed of a moving particle

    PROBLEM Speed of a moving particle The coordinates of a particle moving in the metric xy-plane are differentiable functions of time t with \frac{dx}{dt}=10\frac{m}{sec} and \frac{dy}{dt}=5\frac{m}{sec}. How fast is the particle moving away from the origin as it passes through the point...
  10. T

    Speed & Distance word problems

    I'm really confused. The formula for calculating distance is d=rXt. However, when using this formula my answers are wrong. You spot a car traveling 105 miles per hour. How far does it travel in 10 minutes? D= 105 X .10 my answer: 10.5 miles. However, the correct answer is 17.5 miles You are...
  11. L

    Find the speed of the top of a wheel using calculus

    Hello, I have a question about calculating the speed of the top of a wheel at time t. The wheel has radius 1m and rolls along right along the x axis with speed of a half turn per second. The position vector is: c(t) = ((pi*t - sin(pi*t), 1-cos(pi*t)) I then calculated the velocity vector...
  12. A

    Computing distance by time and speed

    I have multiple records with speed and time. I would like to know what was total distance traveled. Time and speed is changing. Is there any way how to compute this?
  13. A

    Speed, dist and time

    A train completes a journey with a few stoppages at an avg speed of 4km/hr. If it traveled without stopping, it would have recorded an avg speed of 60km/hr. On an avg, how many min/hr does the train stop in the journey?(Hi)
  14. U

    speed, velocity and acceleration

    hey everyone i recently came across a question which asks for speed and in AB calculus the only thing my teacher taught me was velocity. Can anyone explain to me the difference between speed, velocity and acceleration in terms of calculus and their relationship to each other like when velocity...
  15. D

    Converting minutes and speed to km/hr.

    Been stuck on this problem and unsure how to complete. A horse galloped a mile in 2 min 35 s. What was its average speed in km/h? Any thoughts?
  16. P

    torsion of a non unit speed curve

    calculate torsion of y=(sqrt(5)+3cost, 3+tsqrt(7), 1 - 3sint). The usual way I do this is use the frenet formulae for a USC. But y is not USC with speed = 4. So I argued that (1/4)y is USC, found the frenet frame and then torsion t satisfies b'(s)= -tu(s). Found t=sqrt(7)/4 so that torsion of y...
  17. L


    A plane is flying 650 mph in a direction of 12 degrees south of west. Meanwhile, a wind is blowing form the north at 30 mph. Find the resulting speed and direction of the plane. Help please, thanks
  18. J

    Help with calculating a download speed

    Hi everybody I'm trying to calculate a download speed for a homework assignment and I'm struggling a bit. I'm not asking for anybody to answer the question for me, I would just like somebody to explain what I need to do in order to work it out. The question I am struggling with is: If you have...
  19. rcs

    average speed

    Tom drove for 3 hours at 30 km/hr and another 2 hrs at 70km/h. What was his average speed for the journey? attempt: using S = d/t Given: 2 hrs at 70km/h and 3 hrs at 30km/h Solve: 30/3 + 70/2 = (10 + 35 ) /2 = 45/2 = 22.5 km/h please correct me if im wrong. because im not so sure with my...
  20. S

    Math help to speed up algorithm

    Hello. Simply I have a C++ algorithm that performs two types of simple computations randomly and consecutively: or being "x" the result of the previous computation, example: | | | | and so on... The problem is that, after a set of computations, normally the machine gets...