Recently Active Mechanics Questions

There will be an increase in potential energy of the system, if work is done upon the system by ...

A car moves along a horizontal circular road of radius r with velocity v. The coefficient of friction between the wheels and the road is mu . Which of the following statements is not true ...

A block of mass 2 kg is to be lifted with constant velocity by applying force F down the rope that passes over pulley having coefficient of friction μ.Find the value of the pull required. Ans is 2geπμ ...

A particle of mass 1 gm executes an oscillatory motion on a concave surface of radius of curvature 2m. If the particle starts its motion from a point at a height of 1 cm from the horizontal and the coefficient of friction is ...

1)Displacement of a particle is s=0.5t4-5t3+12t2-1.At what instants acceleration of particle is 0? (Ans-5 sec) 2)y=2x3+6x2+8x+120.At what time the particle has greatest speed? (ymin=110,ymax=174) ...

A force overrightarrow{F,}=-K(yhat{i}+xhat{j}) (where K is a positive constant) acts on a particle moving in the xy-plane. Starting from the origin, the particle is taken along the positive x-axis to the point (a, 0) and then ...

using the method of integration for bodies having continuous distribution of mass.... we use... Xcm = 1/M ∫x.dm we all know this (not sure)... but here's what is annoying me... on finding the COM of a ring... we set y = r s ...

A stone tied to a string of length L is whirled in a vertical circle with the other end of string at the centre. At a certain instant of time the stone is at it lowest position and has a speed u. The magnitude of change in ve ...

A particle is moving in aplane with a velocity given by V=V0i +(awcoswt)j where i and j are unit vectors alond X and Y axes resp.The trajectory of the particle if the particle starts from origin at t=0 will be.. A) y=asin(wx/ ...

A thin uniform elastic rod of natural length L,density ρ and Young's modulus Y is just completely immersed in vertical position in fluid of density 2ρ by applying a vertical downward force at its top end. The rod is in equi ...

A thin uniform elastic rod of natural length L,density ρ and Young's modulus Y is just completely immersed in vertical position in fluid of density 2ρ by applying a vertical downward force at its top end. The rod is in equi ...

A certain quarternary star system consists of three stars each of mass m,moving in same circular orbit about a stationary central star of mass M.The three identical stars orbit in same sense and are symmetrically located with ...

A block is given certain upward velocity along the incline of elevation α.The time of ascent to upper point was found to be half the time of descent to initial point.The co-efficient of friction between block and incline is: ...

Plane microwaves from a transmitter are directed normally towards a plane reflector.A detector moves along the normal to the reflector.Between positions of 14 successive maxima , the detector travels a distance 0.13m.Find the ...

Two wires of different densities are soldered together end to end then stretched under tension T.The wave speed in the first wire is twice that in the second wire. (a)If the amplitude of incident wave is A,what are the amplit ...

Suppose there is a pulley with a mass m hanging in one one side of the string and the other side is attached to a vibrator by keeping the string in a horizontal position.The linear mass density of the string is 0.002 kg/m.The ...

Find the net contact force on the 1 kg block.(Take sqrt{5}approx 2 for this question) *Image* ...

Five equal forces of 10 N each are applied at one point and all are lying in one plane.If the angles between them are equal,the resultant of these forces will be: (A)zero (B)10 N (C)20 N (D)10 2 N ...

A truck travelling due north at 50km/hr turns west and travels at the same speed.What is the change in velocity? (A)50km/hr north-west (B)50 2 km/hr north-east (C)50 2 km/hr south-west (D)50 2 km/hr south-east (I had a confus ...

Resonance occurs in a series LCR ckt when the frequency of the applied emf is 1000 Hz.Then (a)when frequency=900 Hz, then the current through the voltage source will be ahead of emf of the source. (b)the impedence of the circ ...

A wind powered generator converts wind energy into electrical energy . assume that the generator converts a fixed fraction of the wind energy intercepted by its blades into electrical energy. for wind speed 'v', the electrica ...

What is the minimum velocity of a projectile to cross a point (a,b) if it starts from the origin? Please show the proof. ...

The figure shows a ray incident at an angle i=π/3 . The ray is refracted and angle of refraction is r. The value of r changes between 0 to π/2when the ratio μ1/μ2 = k is changed. If the plot drawn shows the variation of | ...

In the figure shown a light container is kept in a horizontal rough surface of coefficient of friction μ= sh/v .A very small hole of area s is made at a depth h.Water of volume v is filled in the container.The friction is no ...

Let F,FN and f denote the magnitudes of the contact force,normal force and the friction exerted by one surface on the other kept in contact.If none of these is zero, (a)F>FN (b)F>f (c)FN>f (d)FN-f<F<FN+f ...

A uniform circular hoop is rotating clockwise in the absence of gravity with tangential speed v0 . If v be the velocity of transverse waves travelling on this string then comment on the relationship between v and v0 .(lesser, ...

A man weighing 60kg stands on an immobile platform ( a disc) with a mass of 100 kg.What are the no. of revolutions per minute made by the platform if the man moves along a circle with a radius of 5 mts. around the axis of rot ...

A rod of length L and mass M is fixed at one of its end and is free to rotate about that point.A pendulum of mass m(the bob) and length L also hangs from that position.Now the bob of pendulum is allowed to fall from height L ...

A ROD OA OF LENGTH L IS STANDING ON A SMOOTH GROUND.A SLIGHT JERK SETS THE IN MOTION. THERE IS A POINT P ON THE ROD WHOES LOCUS IS A CIRCLE IN THE SUBSEQUENT MOTION.LOCATE P. ...

If the shear modulus of a wire is 5.9*1011 dyne/cm2, then the potential energy of a wire of 4000 cm in diameter and 5 cm long twisted through a angle of 10 minutes ,in joule,is: (a)1.253*10-12 (b)2.0*10-12 (c)1.0*10-12 (d)0.8 ...