Momentum | MCQs

Explanation

Momentum is the quantity of motion contained in a body.

It is defined as the product of an object's mass and velocity.

Momentum is a vector quantity and is typically represented by the symbol "p".

Explanation

Rotational kinetic energy of a disc about its center:  

K.E = (1/2) I ω², where I = moment of inertia.

For a disc, I = (1/2)MR²,  

So, K.E = ½ × (½ MR²) × ω² = ¼ MR²ω²

If linear velocity v = Rω, then  

K.E = ¼ Mv²

Explanation

Kinetic energy (K.E) in terms of momentum is given by the formula:

K.E = p² / (2m)

Where:  

- p is momentum  

- m is mass  

Explanation

Explanation

The principle of conservation of linear momentum is a direct consequence of Newton's Third Law of Motion.

While Newton's Second Law relates force to the rate of change of momentum (F = dp/dt),

It's the reciprocal action-reaction nature described in the Third Law that leads to the preservation of total momentum in an isolated system. 

Explanation

Momentum is given by the formula: p = mv, where m is mass and v is velocity (or speed).

It depends on mass and speed, not on acceleration, so momentum is independent of acceleration.

Explanation

Momentum (p) is defined as mass (m) multiplied by velocity (v), so p = mv.

If we square p and divide by m, we get: p^2/m = (mv)^2/m = mv^2.

This is the formula for kinetic energy.

Therefore, p^2/m has the same unit as energy. 

Explanation

An alternative unit to kg ms⁻¹ is Ns (Newton-second).

This is because 1 N = 1 kg⋅m⋅s⁻², and multiplying by seconds gives Ns = kg⋅m⋅s⁻¹. 

Explanation

The momentum 

𝑝 of a photon is given by the equation:

𝑝=ℎ/𝜆 

where:

h is Planck's constant,

λ is the wavelength of the photon.

Since photons are massless, their momentum is not related to mass but to their wavelength.

Explanation