Question

A particle moving in xy plane at 2 metre per second along x-axis two second its velocity is 4 metre per second direction making 60 degree with positive x-axis

Answer 1

A particle moves in xy plane at 2m/s along x-axis.

so, initial velocity of particle, u = 2i

after 2 sec, its velocity is 4m/s direction making 60° with positive x -axis.

so, final velocity , v = 4(cos60° i + sin60° j)

= 4(1/2 i + √3/2 j)

= 2i + 2√3 j

we have to find acceleration, a

using formula, v = u + at

or, (2 i + 2√3 j ) = (2i) + a × 2

or, (2i + 2√3 j ) - 2i = 2a

or, 2√3 j = 2a

or, a = √3 j

hence, acceleration of particle is √3 m/s² along positive direction of y-axis.