Question

A 3 kg block, initially moving due east at 6 m/s, is acted upon by an impulse having magnitude 6 Ns and direction due west. The final velocity of the block is

Answer 1

A block of mass 3kg , initially moving due east at 6m/s.

so, initial velocity of block , u = 6 i m/s

block is acted upon by an impulse having magnitude 6N.s and direction due west.

so, impulse , J = -6i N.s

we know, impulse = change in linear momentum.

let final velocity of block is v

then, final linear momentum - initial linear momentum = impulse

or, mv - mu = J

or, 3(v - 6i) = -6i

or, 3v - 18i = -6i

or, 3v = 12i

or, v = 4i m/s

hence, final velocity of the block is 4m/s due east.