List of top Physics Questions on Conservation of energy

A ball falling from a height of 20 m hits a floor and bounces back to a height of 17 m. The percentage of energy lost by the ball during the impact is

A ball falls from a height of 20 m, and then bounces back up to 17 m height. The loss of energy is

A smooth inclined plane ends in a vertical circular loop, as shown in the figure. A small body is released from height $h$ as shown. If the body exerts a force of three times its weight on the plane at the highest point of circle then the height $h = \alpha R$. The value of $\alpha$ is _________.

A rain drop of mass \(10g\) falls from a height of \(50m\) from rest. If the loss of energy due to air resistance is \(3J\), then the velocity of the drop on striking the ground is \((g = 10ms^{-2})\)

Determine Min. Energy released when an electron jumps to ground state in Balmer series from infinity.

A ball of mass $200\, g$ rests on a vertical post of height $20\, m$ A bullet of mass $10 \,g$, travelling in horizontal direction, hits the centre of the ball After collision both travels independently The ball hits the ground at a distance $30 \,m$ and the bullet at a distance of $120 \,m$ from the foot of the postThe value of initial velocity of the bullet will be (if $g=10\, m / s ^2$ ) :

A 12.5 eV electron beam is used to bombard gaseous hydrogen at room temperature. The number of spectral lines emitted will be

Experimentally it is found that 12.8 eV energy is required to separate a hydrogen atom into a proton and an electron. So the orbital radius of the electron in a hydrogen atom is\(\frac{ 9}{x} x 10^{-10}\)m. The value of the x is _____.
(1eV = 1.6 x 10^-19J, \(\frac{1}{4π∈_0}\) = 9 x 10⁹ NM² / C² and electronic charge = 1.6 x 10^-19JC)

The elastic potential energy stored in a steel wire of length 20 m stretched through 2 cm is 80 J. The cross sectional area of the wire is______ mm² . (Given, y = 2.0 x 10¹¹ Nm^-2)

A proton, a neutron, an electron and an α-particle have same energy. If λ_p, λ_n, λ_e and λ_α are the de Broglie’s wavelengths of proton, neutron, electron and α particle respectively, then choose the correct relation from the following:

A sample of an ideal gas is taken through the cyclic process ABCA as shown in figure. It absorbs, 40 J of heat during the part AB, no heat during BC and rejects 60 J of heat during CA. A work of 50 J is done on the gas during the part BC. The internal energy of the gas at A is 1560 J. The work done by the gas during the part CA is

A mass \( m \), suspended vertically by a massless ideal spring with spring constant \( k \), is at rest. The mass is displaced upward by a height \( h \). When released, the kinetic energy of the mass will be proportional to (Neglecting air resistance)

A ball of mass \( m \) is projected upward with a speed \( v_0 \). The speed at a height \( h \) is (Neglecting air resistance)

When a body is projected vertically up from the ground with certain velocity, its potential energy and kinetic energy at a point A are in the ratio 2 : 3. If the same body is projected with double the previous velocity, then at the same point A the ratio of its potential energy to kinetic energy is

In elastic collision

In elastic collision

In elastic collision

A bomb of mass 9 kg explodes into two parts. One part of mass 3 kg moves with velocity 16 m/s, then the KE of the other part is