1. J

    What is the normal force in A and B?

    A welded square frame consisting of four equal rods each with mass m and length 2l can move in the vertical plane by means of two small wheels in A and B that move frictionally along a horizontal or vertical track, respectively. The disc is released from rest in a position where the sides of the...
  2. S

    Calculate the difference between the initial and final masses of the reaction

    Polonium-212 decays into lead-208 emitting an alpha particle. The mass of polonium is 3.51986x10^-25kg the mass of lead is 3.45323x10^-25kg and the mass of an alpha particle is 6.646x10^-27kg
  3. S

    Calculate the mass deficit in this nuclear reaction

    Calculate the mass deficit in this nuclear reaction $12{\rm C}+\frac{12}{6}{\rm C}\rightarrow \frac{24}{12}{\rm Mg}$ Information given: - rest mass of a carbon-12 nucleus: $1.9921157\times 10^{-26}\,{\rm kg}$ - rest mass of a magnesium nucleus: $3.9817469\times 10^{-26}\,{\rm kg}$ -...
  4. S

    Nuclear Reaction - How to determine variables as much as possible

    Hey Guys, exercise: "It is desired to study the first excited state of 16O which is at energy of 6.049 MeV. Using the (alpha, n) reaction on target of 13C, what is the minimum energy of incident alphas which will populate the excited state? So, i suggest to define first the reaction equation...
  5. S

    Normal Reaction in rotating frame.

    Hi there, I'm new to this forum so forgive me if this is in the wrong section. The module I'm studying is a mechanics course as part of a mathematics degree (currently in year 3 of 4), however, I am not confident with physics at all. I have a problem with the following question . . ...
  6. S


    CeF3+ LaF3----> product What product we will get after reaction ?
  7. T

    Heat of Reaction (Enthalpy)

    Well, suppose we have a reaction: |\nu _1| A_1 +|\nu _2| A_2+\cdots \rightleftharpoons |\nu _3| A_3 +|\nu _4| A_4 +\cdots At standard conditions (P_0,T_0)=(1 bar , 298.15 K ) we calculate the enthalpy of reaction via tabulated values of enthalpy of formation: \Delta...
  8. C

    Cancel reaction force

    This triangular moves along the x axes. It is in equilibrium as the spring force Fx=100N from the right is canceled by the reaction on the wall. A roller which moves only along the y axes applies force Fy. Angle θ=25 degrees. No friction, no gravity. How much force Fy is needed in order to...
  9. S

    direction of normal reaction

    hi i was wondering if someone could help me on something based on this thread. statics in general when i look at these type of static questions ( with a object touch a sphere/circle) I am not sure what direction the normal reaction is supposed to be. I understand that it depends on if...
  10. O

    Reaction of the friction

    I am a student from Sri Lanka, According to the newton's third law there is a reaction for the each external force. But I have a problem that what is the reaction of the friction force. Is it form to the direction of moving the object?
  11. L

    Isochorous reaction: metal and acid in autoclave

    Hello, how can I calculate the equilibrium H2- pressure in an autoclave for a reaction like Zinc+ HCl -> H2 at a given temperature. Best Regards Lothar
  12. K

    Working out reaction time?

    Hello, was wondering if anyone could help me in knowing how to work out the following question? You are driving down the M2 at 70 miles per hour, when you see a fox crossing the motorway. If you travel 6.26m before hitting the brakes, what is your reaction time? Thank you kindly xx
  13. L

    support reaction

    I'm asked to find the W and I was told that the rope at C is in tension , there is reaction at B , my question is , is there any reaction at C ? i have tried to do in this way , but i do not get the ans vertical force = 80+10-RB+TC-RC-2W=0 --------equation 1 total moment about A =...
  14. A

    Reaction Force help

    Hi guys, I'm currently working on a homework question but I'm a little bit stuck although I do know what I'm meant to be doing. My question asks me to find the torque being caused by a beam pulling down on another. I'll explain a little more the context of it - there is one beam (beam 1)...
  15. S

    3rd Law of motion

    A horse pulls the cart, if action and reaction are equal how does the horse move?
  16. L

    energy released (nuclear reaction)

    can someone please explain what's this all about? why the energy released involve( proton) is 1.007825(934MeV) +2MeV ??
  17. M

    Reaction forces in BULB ( III Newton problem ))

    1. The problem statement, all variables and given/known data In space we have bulb and two satellites. ( zero friction condition ) Satellites have got mass m and they are using the same (twin) sail Single Satellite mass m (picture below) Problem satellite-------L----------Bulb...
  18. J

    Normal force and gravity force are not action reaction pairs?

    I know that Newton's third law is an action reaction on only two objects. In a situation with a box on the floor, is the reason why the normal force is not an action reaction pair with the force of gravity because there are more than two objects that are in play? I was wondering what in the...
  19. B

    question on fusion reaction

    Require help to understand physics homework problem If hydrogen particles are converted to an alpha particle and a neutron by fusion reaction, then which type of energy released in the reaction? is it a kinetic energy of the alpha particle or kinetic energy of a neutron? Thanks
  20. W

    gibbs free energy for reaction equlibirum

    Hi! I have a problem with a thermodynamic calculation: The reaction is: Mineral1 + Mineral2 + Mineral3 --> Mineral 4 I have got H,S,G(standard state) for the minerals 1 to 3. Fpr the mineral 4 i have got the heat capacity, pressure and thermal expansion. Is it possible to calculate...