rate

  1. P

    Do all object really fall at the same rate regardless of mass?

    Ive always had this question in the back of my mind? Do all objects fall at the same rate regardless of mass? This theory has been tested many times. I just watched a video on youtube where they dropped a bowling ball and a feather at the same time in a giant vacuum chamber. As predicted, they...
  2. T

    Dose rate problem.

    I just want to know the formula for the following question: If the dose rate from a sample of Ra-223 was found to be 20 mSv per hour at 10 micrometres, calculate the dose rate at 30 micrometres. Show your calculations. Give your answer to one decimal place. I think it is 20 mSv x 10...
  3. L

    Decay Rate of Cs Time

    Hello! Here is the question give to me by my teacher: A sample of 137Cs (half-life = 30.1 years) decays at a rate of 10^10 decays per second. How long will it take for the decay rate to decrease to 10^7 decays per second? The work I have done so far is: dN(t=0) = -λNo, where dN(t) =...
  4. C

    Finding volumetric flow rate of heat engine

    A Heat Engine has a thermal efficiency of 40% at a steady power output of 30kW. Calculate the required volumetric fuel flow in L/Hr ( litres/hour) if the fuel has a density of 850 kg/m^3 and an energy content of 45 MJ/kg.
  5. O

    Mass flow rate of water in a hydraulic turbine

    Hello again. I have another problem that I'm working on: The intake to a hydraulic turbine installed in a dam is located at an elevation of 10 m above the turbine exit. Water enters at 20 C with negligible velocity and exits from the turbine at 10 m/s. The water passes through the turbine...
  6. R

    Rate of change im momentum

    Good Day, My name is Rabia. I would like to know he the rate of change in momentum is the same for objects of 2 different sizes if the same size force is acting on it? Can anyone help?
  7. C

    Integration of heat transfer rate equation

    Hi everyone, I am trying to do an analysis of a steam pipeline to compare the use of steam to warm up a pipeline after shutdown versus other methods (heat strips). The one thing I am trying to figure out is the units for the integration of the heat transfer rate equation which is...
  8. D

    Finding melting rate of a ice cube?

    How do i find how long it takes to melt an ice cube? can i use this heat transfer equation below i took the weight of the ice cube and was gonna melt the ice cube in a controlled environment (microwave) and find the rate the heat is transferred from the wattage of the microwave. and i...
  9. J

    Please Help - Calculate Steam Flow Rate

    Hi, I'm sure I'm missing something here. I have a small steam vessel (internal volume 380mL) with an inlet pressure of 55psig (380 kPa) and existing to atmospheric with no change in elevation. I believe that Bernoulli states that velocity is the pressure change over density times volume...
  10. D

    Parallel pipeline flow rate

    Hello to everybody, The problem is given here: My diagram is here: Per problem question, do we need to find Q2 and Q3 which is governed by Q1=Q2+Q3? I am also stuck with the absence of data for viscosity and diameter. How to manage them? Can we express the equation given in the problem...
  11. L

    Finding flow rate

    calculate the flow rate at which oil (kinematic viscocity = (10^-6) (m^2) /s ) flow thru a cast iron pipe 100mm diameter and 115 m long under head difference of 5m this is a question from my book , i suspect the question is lack of information , so the question cant be done , am i right ?
  12. S

    Flow rate in different pipe diameters

    Hello, I need to calculate the flow rate of fluid at the end of the series of pipes with different diameters. I know the pressure head and the density of the fluid. Could anyone help me on how should I approach with this problem.
  13. G

    Area underneath a rheogram (shear stress, shear rate)

    Consider the following rheogram: http://i.imgur.com/x4B2swU.jpg Finding the area underneath a stress-strain graph gives you the toughness, while finding the area underneath PV diagram gives you the work done. What does the area under a rheogram give, and does it have any significance when...
  14. L

    flow rate in a moving pipe

    for part c , why when the vane is moving , the flow rate doesn't change ? ? The flow rate is given by the formula Q=Av , where A = area , v = velocity . IMO , when the velocity of vane change , the flow rate is no longer 0.687kg/s , it should be 0.68kg/s = (10^3)(A)(24) , A= 2.83x10^-5...
  15. K

    How to determine shear rate in rotating plate?

    Hello, I was wondering how to determine shear rate in rotating plate as below. I believe the plate length (L) and height (H) should have influence on the magnitude of shear rate. What would be relationship between shear rate and plate length/height? Is there any publication about that...
  16. K

    How to determine shear rate in rotating plate?

    Hello, I was wondering how to determine shear rate in rotating plate as below. I believe the plate length (L) and height (H) should have influence on the magnitude of shear rate. What would be relationship between shear rate and plate length/height? Is there any publication about that? Thank...
  17. L

    volume flow rate

    what is G and γ mean here ?
  18. R

    Flow Rate Through a Crack on Tank

    Hello there I am trying to find a flow rate through a crack on a water tank shown below for H= 4.0 m and t= 3 cm. Any help is appreciated. Picture of the question is uploaded. http://postimg.org/image/v6qyfbzpd/
  19. B

    Dynamic Spring Rate formula

    Hi guys, I am trying to find a formula to calculate dynamic spring rate. Here is what I have to work with. Spring rate: 200# Static on the car: 1000# Spring travel: 3" Dynamic Load, car going through turns, 2200#
  20. B

    Water Flow Rate Through 1/2 Cu Tube

    Hello. I wanted to get a general sense on expect water flow through a 1/2 copper tube. I have 60 feet of level 1/2 copper tube. I want to get 8 gpm flow out at 80psi pressure in. I understand that there are other variables that may affect flow. However, can someone give me a sense of what...