Recent questions tagged work-power-energy

A block of mass 1.6 kg is attached to a horizontal spring that has a force constant of $1.0 \times 10^3 N/m$. The spring is compressed 2.0 cm and is then released from rest. Calculate the speed of the block as it passes through the equilibrium position $x= 0$ if the surface is frictionless.

asked Aug 25, 2014 by balaji.thirumalai

1 answer

A 2 Kg wood block is on a level board and held against a spring of spring constant k=100 N/m which has been compressed .1 m. The block is released and pushed horizontally across the board. The coefficient of friction between the block and the board is $\mu_k = .2$. Find the velocity of the block just as it leaves the spring.

asked Aug 25, 2014 by balaji.thirumalai

1 answer

A spring with a spring constant of 250 N/m has a length of 0.5 meters at rest. What magnitude of force is needed to stretch the spring so that is 0.75 meters long?

asked Aug 25, 2014 by balaji.thirumalai

1 answer

Which of the following is true, if no work is done by a force on an object?

asked Aug 25, 2014 by balaji.thirumalai

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A roller coaster pictured below starts at point $A$ and speeds down a curved track with speed $u$. Assume that the friction between the roller coaster and the track is negligible even though it always stays in contact with the track. What is the speed of the roller coaster at point $B$?

asked Mar 22, 2014 by balaji.thirumalai

1 answer

A body of mass m moving with velocity v collides head on with another body of mass $2m$ which is initially at rest. The ratio of K.E of colliding body before and after collision will be

asked Aug 9, 2013 by meena.p

1 answer

Two masses of $0.1\;kg$ and $0.4 \;kg$ move towards each other with velocities $1 m/s$ and $0.1 m/s$ respectively. After collision they stick together . In 10 seconds the combined mass travels

asked Aug 9, 2013 by meena.p

1 answer

Two balls at same temperature collide inelastically which of the following are not conserved 1) Kinetic energy 2) Velocity 3) temperature 4) momentum

asked Aug 9, 2013 by meena.p

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A tennis ball dropped from height of $2m$ rebounds only $1.5 m, $ after hitting the ground , What fraction of energy is lost in the impact

asked Aug 8, 2013 by meena.p

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A spring 40 mm long is streched by application of a force. If 10 N force is required to stretch the spring through 1 mm, then work done in stretching the spring through 40 mm is

asked Aug 8, 2013 by meena.p

1 answer

If momentum of boby increases by $0.01 %$ its kinetic energy will increase by

asked Aug 8, 2013 by meena.p

1 answer

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

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

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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

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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

A cord is used to lower vertically a block of mass M,a distance d, at a constant downward acceleration $g/4$. Then work done by cord on block

asked Aug 6, 2013 by meena.p

1 answer

A $1.0 \;kg$ block collides with a horizontal weightless spring of spring constant $2.0N/m$. The block compresses the spring $4.0\;m$ from the rest position.Assuming that the coefficient of kinetic friction between the block and horizontal surface of $0.25,$ what was the speed of the block at the instant of collision

asked Aug 6, 2013 by meena.p

1 answer

Graph shows the acceleration of a 3 kg particle as an applied force moves it from rest along x-axis. The total work done by the force on the particle by the time the particle reaches $x=6\;m$ is equal to

asked Aug 6, 2013 by meena.p

1 answer

A particle of mass m slides a distance d down a plane inclined at $\theta$ to the horizontal. The work done by the normal reaction R is

asked Aug 6, 2013 by meena.p

1 answer

A car is moving with a constant speed of $20 ms^{-1}$ against a resistive force of $100 \;N$. The power exerted by the car is

asked Aug 6, 2013 by meena.p

1 answer

A 1.5 kg block is initially at rest on a horizontal frictionless surface when a horizontal force in the positive x-axis direction is applied to the block . The force $\hat F$ is given by $\hat F=(4-x^2)\hat i \;N$ . Initial position of the block is $x=0$. The maximum kinetic energy of block between $x=0$ to $x=2.0$ is

asked Aug 6, 2013 by meena.p

1 answer

Two blocks A and B of mass m and 2m are connected by a massless spring of force constant k. They are placed on smooth horizontal plane . Spring is streched by an amount x and then released . the relative velocity of the blocks when the spring come its natural length is

asked Aug 6, 2013 by meena.p

1 answer

Velocity - time graph of a particle moving in a straight line is shown. Mass of particle is 2 kg. What is work done by all the forces on the particle in time interval between $t=0$ to $t=10s$ if velocity goes from $10 ms^{-1}$ to $-20 ms^{-1}$ ?

asked Aug 6, 2013 by meena.p

1 answer

An object of mass m is allowed to fall from rest along a rough inclined plane. The speed of the object at bottom of the plane is proportional to

asked Aug 5, 2013 by meena.p

1 answer

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