# Search results

1. ### Amusement Rotor Ride Explanation

here the normal reaction by the wall is due to centrifugal force of the cylinder condition for a person to held up inside is μsFcf=mg
2. ### Moment of inertia of a set of spinning disks

i'm just answering to your question b. parallel axis theorem is also comes from the base I=Σmiri^2 ie,for a disk at a distance x from o,I=Σmi(ri+x)2 =Σmiri^2+Σmix2+Σmi2rix =Σmiri^2+Mx2
3. ### Moment of inertia of a set of spinning disks

the actual M.I is not like that it must calculated by calculating M.I of each disks about o it may be near to the M.I of the rod with width L/15 given above ,(answer to 2nd question)...
4. ### Moment of inertia of a set of spinning disks

a rod of mass M and length L has moment of inertia,I=ML2/12 but it is only for a thin rod here the rod is a line passing through centers of disks,it's M.I constitute only small part of total M.I of the arrangement here,the moment of inertia the arrangement is comparable to the M.I of a rod of...
5. ### Charges inside a metal sphere will tend to go towards

i think charges will go to the surfaces if there is excess charge(suppose +ve) inside the metallic sphere in static situation it will produce electric field.then free electrones move to the +ve charge to neutralize it.movement of free electrones cause +ve charge somewhere else.ie,the metallic...

7. ### Grabber - statics example

i think the frictional force balance the wight of the box.we have to give the normal force on the box that give rise to the friction by giving a torque to the grabber
8. ### Bernoulli Equation and Velocities

sir I have a doubt why component of gravitational force doesn't matter here when tap is at an angle considering a fluid part it has 2 forces on it 1 by the pressure or weight created by fluid part above it and gravitational force on it. please coeerct me if I am wrong
9. ### Archived 'Kinematics - Vector Derivative' Exercise

the rotation of body3 also influence the centrifugal force on the cursor and distance it moved against spring force when body3' z3 axis become parallel to z2 axis total mass=m2+m3 cursor moves x distance from equilibrium position where kx=(m2+m3)(a+x)(theeta point)^2 when body3 moves 90degrree...
10. ### Evaluate Problems using fluid dynamics

but water also excert pressure on the plate contributing to the force
11. ### Rotational kinematics of a spherical rock upon collision

by momentum conservation (M+m)V=mv V=mv/(M+m) force on large rock,F=change in momentum by time=m(v-V)/t=mv(1-1/(M+m))/t torque on it,T=RFsinx=RFa/R=Fa ang.momentum,L=Tt=Fat=mv(1-1/(M+m))a
12. ### Evaluate Problems using fluid dynamics

pressure on the flat plate where water hits,F/A2=p2+density/2(v2^2) (when P by air=0(considering plate near to exit))
13. ### Evaluate Problems using fluid dynamics

the force is due to the pressure of moving fluid there F=P*A
14. ### Thermodynamic equation from textbook

you said that exothermic reaction under adiabatic condition the T will rise.then why the system do expansion work to maintain T constant

16. ### Adiabatic Process, Internal Energy vs. Enthalpy.

How nCvΔT will equal to W.It is the heat absorbed/released at constant volume only(no work is done at constant volume,the expression Cv).i think instead of work it is heat,ie ΔU=ΔH=qv at constant volume and ΔH=qp at constant pressuer actually it is the proof for Cp-Cv=R
17. ### Thermodynamic equation from textbook

you said ΔU for a reaction is caused by the bond dissociation and formation. i want to know more about it(why here T remains same) why in phase change also T remains constant(if there isn't any kinetic energy change if solid/liquid→gas and vice-versa that cause T difference) then what cause ΔU
18. ### Resultant Impulse

impulse is the change in momentum(FΔt=ΔP-Newtons 2nd law) but here ΔP=0=impulse
19. ### Archived 'Kinematics - Vector Derivative' Exercise

is the movement of cursor is a part of the system.(it suffers a psudo force in x-dir=Zo/2*theeta2 ) so it's movement away from the Zo axis is easier
20. ### How do I calculate distance from acceleration and velocity?

you have mistaken in attempting question b only x2-100 gives the displacement in the time of disceleration and x2 is the total displacement and you calculated it has 300m(correct)
21. ### Thermodynamic equation from textbook

yeah I get you. so for a isothermal reaction process ΔU is the energy used for bond dissociation,formation,etc.the excess heat will removed sometimes by doing a work. 1.I heard phase transformation is a isothermal process what about ΔU? 2.what is difference b/w ΔU in isothemall process and not...
22. ### Thermodynamic equation from textbook

it is a function of state
23. ### Thermodynamic equation from textbook

in your post the T is constant so the supplied heat must be fully use to do work so the in U from constant V to that P will be zero so overall change will be ΔU But here the reaction takes place at constant V not at constant P.(we add or remove heat after the reaction)
24. ### Thermodynamic equation from textbook

we take two separate systems and allow the same reaction to proceed in both with one at constant V and other at constant P(at constant T)
25. ### Thermodynamic equation from textbook

You may think this, but it is not correct. Have you considered the amount of energy involved in making and breaking chemical bonds? When chemical reactions occur, this affects ΔU and ΔH. If an exothermic reaction occurs at constant pressure and temperature, ΔH is negative, and heat must be...
26. ### Thermodynamic equation from textbook

but how in a chemical reaction(in general) the amount of mass change(since U changes when 1.heat passes 2.work done 3.matter enters or leaves ) it will violate the law of mass conservation. i think if a reaction takes place at constant T the heat evolved(ΔH) must fully use for doing...
27. ### Thermodynamic equation from textbook

In my text it was said that ΔH=ΔU+ΔnRT H:ENTHALPY U:INTERNAL ENERGY Δn:n of gaseous products-gaseous reactents they use ΔnRT instead of Δ(PV),here T is constant⇒U is a constant(U is a function of temperature) then why didn't the term ΔU became zero? what is the actual equation?is it is...
28. ### Rolling motion

what is the diffrences in the both cases(direction of friction)?
29. ### Rolling motion

if a central force acts on a sphere it will rotate and move and also a angular momentum is given to that body it will also move in the same manner.What provide torque in first case and net force in second case.is it friction then how?
30. ### Accelerating pulley tension

we have tension=(2Mm)g/M+m,but the acceleration of the system is a=F/(M+m)-g.The system has a psudo force acting in the bodies and so tension=(2Mm)(g+a)/M+m=2Mmg/(M+m)+(2Mm)F/(M+m)^2-2Mmg/(M+m)=(2Mm)F/(M+m)^2 acceleration of larger body,M=Mg-(2Mm)F/(M+m)^2