Recent questions tagged class11

Two small particle of equal masses start moving in opposite direction from A in a horizontal circular path of radius r Their tangential velocity at A are v and 2v, respectively as shown. Where will be the first collision in the path of the circle.

asked Aug 8, 2013 by meena.p

1 answer

If the ratio of the roots of $ax^2+bx+c=0$ is equal to the roots of the equation $ x^2+x+1=0$, then $a,b,c$ are in ?

asked Aug 8, 2013 by rvidyagovindarajan_1

1 answer

A jet airplane is travelling at $200 m/s$ The engine takes in $100\;m^3$ of air having mass $100 \;kg$ each second. The air is used to burn 5 kg fuel each second. The energy is used to compress the products of combustion and to eject them at the rear of the plane at $500 m/s$ relative to the plane. The thrust of the engine is

asked Aug 8, 2013 by meena.p

1 answer

A particle is projected vertically upward with a speed of $16 m/s$, after some time, when it again passes through point of projection, its speed is found to be $8 m/s$. It is known that the work done by air resistance is same during upward and downward motion, Then the maximum height attained by the body is ? $(g=10 m/s^2)$

asked Aug 8, 2013 by meena.p

1 answer

A particular force acting on object has equation $F=-cx^3$ where x is displacement of object from some orgin and $c=1N/m^3$ What is magnitude of the work done by this force, as the object moves from $x=-2m,\; to\;x=+2m$

asked Aug 8, 2013 by meena.p

1 answer

A body of mass 3 kg under constant force which causes a displacement $s$ in meters in it given by $s=\large\frac{1}{3}$$t^2$ work done by the force in $2$ seconds is

asked Aug 8, 2013 by meena.p

1 answer

A particle of mass m is moving in a circular path of constant radius 'r'. Such that the centripetal acceleration $a_c$ is varying with time as $a_c=k^2rt$ where R is a constant. What is the power on the particle

asked Aug 8, 2013 by meena.p

1 answer

An electron of mass $'m'$ moving with velocity $'v'$ collids head on with an atom of mass M. As a result of the collision a certain fixed amount of energy $\Delta E$ is stored internally in the atom. The minimum initial velocity possessed by the electron is

asked Aug 8, 2013 by meena.p

1 answer

Under the acting of a force P, the body can't moves up an incline from initial position $x_1=-150 mm$ to $x_2=80\;m$ where $x=0$ is the unstreched position of the spring along the incline. Find the work done by the spring

asked Aug 8, 2013 by meena.p

1 answer

A bob of pendulum of length 2 m describes an are of a circle in a vertical plane. If the lension in the cord is $2.5$ times the weight of the bob for the position shown, find the velocity of the bobs at that position.

asked Aug 7, 2013 by meena.p

1 answer

A block rests on an inclined plane. A spring is attached is a pulley and is pulled downward gradually with increasing force. $\mu $ is the coefficient of friction between block and inclined plane . Find the potential energy of the spring at the momentum when block begins to move for a force constant k of spring $[\theta= 30^{\circ}]$

asked Aug 7, 2013 by meena.p

1 answer

A uniform chain of length l and mass m is placed as shown . Find the gravitational potential of chain

asked Aug 7, 2013 by meena.p

1 answer

The given graph shows the motion of a particle of mass $10/7\; kg$ the action of an external agency with power. Its initial position is $x=0$ and initial velocity is $1 m/s$ . velocity at $x=10 m$ is (use the graph)

asked Aug 7, 2013 by meena.p

1 answer

A partical is projected along a horizontal field whose co-efficient of friction varies $\mu = \large\frac{A}{x^2}$ where x is a distance from origin in meters and A is a positive constant. The initial distance of particle is 1m from orgin and its velocity is radially outwards. The minumum initial velocity at this point so that the particle never stops is

asked Aug 7, 2013 by meena.p

1 answer

A pendulum bob of mass m carying a charge 'q' is at rest with its string making an angle $\theta$ with the vertical in a uniform horizontal electric field E. The tension in the string

asked Aug 7, 2013 by meena.p

1 answer

A block of mass $0.50\;kg$ is moving with speed of $2.00 m/s$ on a smooth surface. It strikes another mass of $1.00 kg$ at rest and they move together as a single body. The energy loss during collision is

asked Aug 7, 2013 by meena.p

1 answer

A horse pulls a wagon with a force of $360\; N$ at an angle of $60^{\circ}$ with horizontal at a speed of $10 km/hr$. The Power of the horse is

asked Aug 7, 2013 by meena.p

1 answer

An object is displaced from point $A(2m,3m,4m)$ to a point B $(1m, 2m, 3m) $ under a constant force. $\hat F=(2 \hat i+3 \hat j+4 \hat k)$. Find the work done by the force

asked Aug 7, 2013 by meena.p

1 answer

A smooth narrow tube in the form of an arc AB of a circle of center O and radius r is fixed so that A is vertically above O and OB is horizontal. Particles P and Q of mass m and 2m respectively. with a light in extensible string connecting them (length $\large\frac{\pi\;r}{2}$) are placed inside the tube with P at A and Q at B. and released from rest. Assuming that the string remains during motion, find speed of particles when P reaches B

asked Aug 7, 2013 by meena.p

1 answer

A train of mass $2.0 \times 10^5$ kg has constant speed of $20 m/s$ up a hill inclined at $\theta, (\sin \theta=\large\frac{1}{50})$ to the horizontal when the engine is working at $8.0 \times 10 ^5 $ watt. Find the resistance to the motion of the train $(g=9.8 m/s^2)$

asked Aug 7, 2013 by meena.p

1 answer

A block of mass $0.80 kg $ is attached to a cord passing through a hole in a horizontal frictionless surface. The block is originally revolving at a distance of $0.30 m$ from the hole with a speed of $0.80 m/s$ The cord is pulled from below the hole, shortening the radius of circle in which the block revolves to $0.10 m$. At this new distance the speed of block is $2.40 m/s$. How much work is done by person who pulled the cord?

asked Aug 7, 2013 by meena.p

1 answer

Two masses $m_1$ and $m_2$ connected by light spring rests on horizontal plane. The coefficient of friction between the masses and surface is $\mu$. What minimum force has to be applied in horizontal direction to the mass $m_1$ in order to shift the mass $m_2$ $ (g= 10 m/s^2)$

asked Aug 7, 2013 by meena.p

1 answer

An objecte of mass 5 kg falls from rest through a vertical distance of 20 m and reaches velocity 10 m/s. How much work is done by push of air on the object $(g=10 m/s^2)$

asked Aug 7, 2013 by meena.p

1 answer

In the arrangement as shown a mass m is released from rest with spring unstreched.What is the speed of block at equillibrium position

asked Aug 6, 2013 by meena.p

1 answer

A cyclotron is used to accelerate protons deuterons, $\alpha$- particles etc. If energy attained after acceleration by proton is E, the energy attained by $\alpha$- particle shall be

asked Aug 6, 2013 by meena.p

1 answer

The potential energy of a 1 kg mass free to move along the x-axis is given by $V_{(x)}=\bigg[\large\frac{x^4}{4}-\frac{x^2}{2}\bigg]$$J$ The total mechanical energy of the particle is $2J$ then the maximum speed is?

asked Aug 6, 2013 by meena.p

1 answer

An object of mass m is lied to a string of length l and a variable horizontal force is applied on it which is initially zero and gradually increases until the string makes an angle $\theta$ with the vertical. Work done by the force F is

asked Aug 6, 2013 by meena.p

1 answer

A particle moves with velocity $v= (5 \hat i -3 \hat j+6 \hat k) m/s$ under the influence of a constant force $\hat F=(10 \hat i+10 \hat j+20 \hat k)N$. The instantaneous power applied to the particle is

asked Aug 6, 2013 by meena.p

1 answer

A body moves a distance 10m along a straight line under the action of force $5N.$ If the work done is $25J$, the angle which the direction of motion of body is

asked Aug 6, 2013 by meena.p

1 answer

A block of mass m is being pulled up a rough inclined by an agent delevering constant power P. The coefficient of friction between block and incline is $\mu$. The maximum speed of the block during the course of ascent is

asked Aug 6, 2013 by meena.p

1 answer

The potential energy of a force field $\hat F$ is given by $v(x,y)=\cos (x+y)$ . The force acting on the particle at position given by coordinate $(0, \large\frac{\pi}{4})$ is

asked Aug 6, 2013 by meena.p

1 answer