Potential Energy

IMPORTANT

Potential Energy: Overview

This topic covers concepts, such as Potential Energy, Zero Level of Potential Energy, Position Dependence of Conservative Force and its Potential Energy, Spring Forces, Work Done by Spring Force & Energy Stored in Spring etc.

Important Questions on Potential Energy

EASY
IMPORTANT

A conservative force of (-3i^) N acts on a body of mass 3 kg. The change in potential energy of the body due to the force, when it undergoes a displacement (6i^)m is

 

HARD
IMPORTANT

The variation of potential U of a body moving along X axis varies with the position x as shown in the figure.The body is in equilibrium state in

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MEDIUM
IMPORTANT

For the situation shown in the figure, horizontal spring and the spring connecting blocks B and C are light. The blocks A,B and C are of same mass m. The pulley is smooth and fixed. The accelerations of A, B and C just after cutting the horizontal spring are

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EASY
IMPORTANT

The force exerted by a special compression device is given as function of compression x as Fxx=kxx-l for 0xl, where l is the maximum possible compression and k is a constant. The force exerted by the device under compression is maximum when compression is:

HARD
IMPORTANT

In the given diagram system is in equilibrium. If applied force F is doubled how much distance, the mass less block will more towards right before new equilibrium is achieved.

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EASY
IMPORTANT

As shown in the figure, an iron block A of volume 0.25 m3 is attached to a spring S of unstretched length 1.0 m and hanging to the ceiling of a roof. The spring gets stretched by 0.2 m. This block is removed and another block B of iron of volume 0.75 m3 is now attached to the same spring and kept on a frictionless incline plane of 30° inclination. The distance of the block from the top along the incline at equilibrium is

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HARD
IMPORTANT

Two blocks A and B of equal mass 2kg are arranged as shown with springs S1 and S2. Spring S2 is pulled with force F=6 N. Acceleration of block B is 4 m s-2 towards right at an instant. If F is suddenly removed at this instant, the instantaneous acceleration of A and B will be (assume no friction)

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HARD
IMPORTANT

A bead of mass m moves along a smooth fixed ring in a gravity free region. The ring has radius R. The bead is attached to a spring of force constant K and natural length R. The other end of the spring is fixed to a point P on the ring. At an instant shown in the figure when length of spring was 1.6 R, force applied by the ring on the bead was zero. Rate of change of speed of the bead at this instant will be

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MEDIUM
IMPORTANT

A particle of mass 2kg is attached with a spring of stiffness 72 N m-1. When block is at x=1 m it moves with maximum speed. The block moves with 24 m s-1 while passing through x=4 m. Find out the x coordinates in m where it's velocity will be zero.

EASY
IMPORTANT

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

EASY
IMPORTANT

When, two ends of an ideal spring are pulled apart increasing its length it produces force equal to kx at its ends. At a point 14 of its length from one end, the force is

EASY
IMPORTANT

Two blocks A&B with mass 4 kg and 6 kg respectively are connected by a stretched spring of negligible mass as in figure. When the two blocks are released simultaneously the initial acceleration of B is 1.5 m/s2 westward. The acceleration of A is:

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EASY
IMPORTANT

The spring constant of the spring of a gun is k newton/meter. The spring has been compressed x meter from its normal position and a bullet of mass m has been put in the barrel. If the friction is negligible then on firing the gun, the bullet shall have a velocity of m/sec:

EASY
IMPORTANT

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From a fixed support O, hangs an elastic string of negligible mass and natural length L. Masses m1 and m2 attached at the lower end, elongate the string to 2 L. When m2 is removed gently, m1 is able to bounce back to O. The ratio m2/m1 is (assume that the string does not obstruct the motion of m1 )

MEDIUM
IMPORTANT

The system shown in the figure is released from rest. Pulley and spring are massless and friction is absent everywhere. The speed of 5 kg block when 2 kg block leaves the contact with ground is K=40 N m-1 & g=10 m s-2

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EASY
IMPORTANT

K is the force constant of a spring. The work done in increasing its extension from l1 to l2 will be

EASY
IMPORTANT

Water stored in a dam posseses

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A body is falling from a height h. After it has fallen a height h/2, it will possess_____.

EASY
IMPORTANT

Water stored in a dam possesses_____.

EASY
IMPORTANT

A car is accelerated on a levelled road and attains a velocity 4 times of its initial velocity. In this process the potential energy of the car_____.