Question

Can the law of conservation of linear momentum be applied for a body falling under gravity ? Explain

Answer 1

nope, The law of conservation of linear momentum cannot be applied for a body falling under gravity.

let's understand the fact !

let a body of mass m is falling from height h.

initial velocity, u = 0

final velocity, v = √(2gh)

so, initial momentum of body, Pi = mu

= m × 0 = 0

final momentum of body , Pf = mv = m√(2gh) ≠ 0

it is clear that Pi ≠ Pf

we know, conservation of linear momentum, initial momentum, Pi= final momentum, Pf

but here, condition doesn't follow so, law of conservation of linear momentum cannot be applied for a body falling under gravity.