Question

a body of mass m starts from rest with a constant power .If the velocity of the body at the displacement s is v, then the correct alternative is what?
a) S proportional to v. b)s to v2
c)s to v3. d)s to v4

Answer 1

Hey Dear,

◆ Answer - (c)

s ∝ v³

◆ Explanation -

Given that particle starts its motion at rest.

v² = u² + 2as

v² = 0² + 2as

2as = v²

a = v²/2s

Now power is given by formula -

P = F.v

P = m.a.v

P = m × v²/2s × v

P = mv³/2s

s = mv³/2P

For this object, m & P are constant, hence s ∝ v³.

Thanks dear...