1. ### Time needed for a Force F to accelerate the crate to 2m/s? (Dynamics)

So above is the question. The picture below is my attempt at the solution: However the answer at the back of the book suggest that T=1.929s
2. ### The path of the 3.6-kg particle P is an ellipse

Homework Statement 13.71 The path of the 3.6-kg particle P is an ellipse given by ##R = \frac {R_0} {(1+ecosθ)}##. where R_0 = 0.5m and e=2/3. Assuming that the angular speed of line OP is constant at 20 rad/s, calculate the polar components of the force that acts on the particle when it is at...
3. ### A package of mass m is placed inside a drum

Homework Statement 13.69 A packege of mass m is placed inside a drum that rotates in the vertical plane at the constant angular speed ##\dot {θ} = 1.36 rad/s##. If the package reaches the position θ = 45deg before slipping, determine the static coefficient of friction between the package and...
4. ### The pendulum is released from rest with θ = 30deg

Homework Statement 13.54 The pentulum is released from rest with θ = 30deg. (a) Derive the equation of motion using θ as the independent variable. (b) Determine the speed of the bob as a function of θ. The solutions given in the textbok are a) ##\ddot θ = -4.905sinθ rad/s^2## b) ##6.26\sqrt...
5. ### Calculate the angular velocity and angular acceleration (pendulum)

Homework Statement 13.53 The tension in the sting of the simple pendulum is 7.5N when θ=30deg. Calculate the angular velocity and angular acceleration of the string at this instant. Homework Equations The Attempt at a Solution Is this correct?
6. ### Banked Curve-Determine smallest static coefficient of friction

Homework Statement 13.49 The flatbed railway car travels at the constant speed of 80 km/h around a curve of radius 55m and the bank angle 15deg. Determine the smallest static coefficient of friction between the crate and the car that would prevent the crate of mass M from sliding. Homework...
7. ### Determine stopping distance of a train traveling at 20m/s

This is problem 12.81 from Pytels Dynamics 2nd edition 1. Homework Statement A train traveling at 20m/s is brought to an emergency stop. During braking, the acceleration is a=-(7/4)+(t/16) m/s^2, where t is the time in seconds measured from when the brakes were applied. (a) Integrate the...
8. ### Pytels Dynamics 12.58: A projectile, launched with an initial v = 24 m/s at angle θ=60 degrees

Homework Statement A projectile launched at A with an initial velocity of 24 m/s at the angle θ=60deg, impacts the vertical wall at B. Neglecting air resistance, calculate the height h Homework Equations The Attempt at a Solution Here is my solution As you can see to find height h I...
9. ### Pytels Dynamics 12.39: A rocket is launched vertically

Homework Statement A 2000-kg is launched vertically from the surface of the earth. The engine shuts off after providing a constant propulsive force of 60 kN for the first 20 seconds. Neglect the reduction in the mass of the rocket due to the burning of the fuel and the variation of the...
10. ### Pytels Dynamics 12.35: A cart carrying a small package

Homework Statement The cart carrying the small 9-N package A is moving up the incline with constant acceleration α. If the package stays at rest relative to the cart in the position θ=45deg, determine the value of α. Neglect friction. Homework Equations The Attempt at a Solution [/B] Are...
11. ### Kinetics question (Chemical engineering)

Hey! I have a question regarding this question that I have to answer. It is about the kinetics of a substance X whose product is 2Y. It is in Swedish and here is the translation: The absorbance of a 0,030M-solution of X was calculated with the help of a Spectrometer. The Spectrometer was...
12. ### Fischer-Tropsch Conversion / Kinetics

Hi, We are currently working on a small-scale Fischer-Tropsch process. The modeling software we are using is HYSYS (Aspen). We want to produce X barils of oil / day using syngas (H2:CO ratio 2:1) using cobalt catalysts. The problem we are currently facing is that we do not have the kinetics...
13. ### I Energy Conversion With Supercritical Fluids

Technically, this isn't a question concerning supercritical fluids. It's more about converting thermal energy into velocity by playing "keep-away" with molecules that want to go supercritical. The idea is simple. In an fully contained system, we can more or less say volume is static...
14. ### Stuck with 2D kinetics problem

Homework Statement Hi, I've been trying to solve this exercise for the last four hours and I'm totally stuck. The problems goes like this: Given the mechanism in the image, located in the vertical plane, the OB cord is cut when t=0. Find the reactions Rx, Ry and N in {Kgf} for the instants...
15. ### Chemistry Kinetics help

Homework Statement Hydrolysis of ethyl lactate Determine the value of the rate constant for the hydrolysis of ethyl lactate from the following data. Mass of ethyl lactate (grams): 0.5956 Concentration of stock HCl solution (M): 0.01023 Standardization titration volumes (of NaOH): Run...
16. ### Kinetics with pressure

This post is not about a homework problem but about a derivation When i was flipping through a physical chemistry book I found a formula which looked like How ever I am clueless to what it is Can anyone explain what it is for And possibly Derive it Thank you
17. ### Magnitute and Direction of Electric Field Based on Particle

Homework Statement A positively charged particle initially at rest on the ground accelerates upward to 180 m/s in 2.70 s .The particle has a charge-to-mass ratio of 0.100 C/kg and the electric field in this region is constant and uniform. What are the magnitude and direction of the electric...
18. ### Activation energy and pre exponential factor

Homework Statement Calculate activation energy and pre exponential factor, i need help with the pre exponential factor Homework Equations Temperature °C -20 = 253 k -10= 263 0=273 10=283 20=293 Rate const. s-1 1.15 3.85 11.3 28.7 74.0 The Attempt at a Solution i already plotted the graph on...
19. ### Help with a mechanics problem from Kleppner's book

Homework Statement An elevator departs the ground at t=0 With uniform velocity. At T1 a boy drops a marbel through the floor of the lift that falls under constant acceleration g=9.8 ms^-2. If it takes marbel T2 time to fall down, what was the height at the T1. Homework Equations h=vT1 h= vT2...
20. ### Chemical kinetics

Homework Statement The task is the following: If the concentration of A decreases 0.03 M in one hour, then the concentration of B should to, which means, [ B] should be 0.05 M? And if I try to calculate k, i get 14.87 l/(mol*h) For second order reactions, t1/2 sould be 1/(k*[A]0) So I get...
21. ### Effects of Crushing a Solid on Equilibrium Position

Hi everyone. So I have been learning about equilibrium recently in class... and suppose I have the following reaction: A(s) + B(aq) <-----> C(aq) + D(g) [Note: in parentheses, I indicate the state of my substances] So I was told recently that pulverizing my solid "A" would not change the...
22. ### Activation energy of parallel reaction

Well,I know that the activation energy of a parallel reaction can be determined by the arrhenius equation as (e1k1+e2k2)/(k1+k2) where e1,k1 and e2,k2 are the activation energies and rate constants for the two reacations.now consider the reaction A》B,and A》C since at every instant the reacted...
23. ### Banked Curve - Minimum Turn Radius

Homework Statement A car travelling 10 m/s is moving along a track banked at 5 degrees. The tire-road friction coefficient is .3 What is the minimum radius it can travel without slipping? v0= 10 m/s Bank Angle Θ = 5° μ=0.3 Note I am working through prep material for the exam. The solution...
24. ### Recognize this irreversible equation for kinetic modeling?

Hi all, I'm trying to come up with velocity equations for a multi-enzymatic system and came across this velocity equation. Does anyone recognize this equation? There was no citation or derivation and the variables were not explained. This is my guess: P, Q, A, B are concentrations of some...
25. ### Deriving a rate equation

Homework Statement Overall reaction: A + F = I + J (just take = as the equilibrium sign) It is first order in both A and B. The following mechanism has been proposed: 1. A + B = C + D 2. C + D = E + B (B is the catalyst) 3. E + F = G + H 4. G + H = I + J These are all...
26. ### Kinetics question: calculating rate constants

Homework Statement I need help for this kinetics question: Chlorination of butene at 0 degrees c, liquid phase, dichloromethane as solvent. initial concentration of butene is 0.1M conversion of 47.71% achieved after 3.1 hours. an additional 0.5M of hot butene was added at this point, which...
27. ### Enzyme Kinetics- is my summary correct?

I have been looking at this enzyme kinetics stuff forever and was trying to come up with a summary for things... #=_= Is this even right...? :/ |---------------|This segment I'm calling "Part 2" k1 k2 E + S ES E + P k-1 |---------------|This...
28. ### Equilibrium Constants

Consider the following generic equilibrium: aM + bN ⇌ cO + dP An equilibrium constant, K, can be defined as: $$K = \frac{[O]^c [P]^d}{[M]^a [N]^b}$$ But couldn't we also define another equilibrium constant similarly with coefficients that are in the same ratio as our original equation? For...