Question

A particle is projected with velocity u at an angle alpha from a point p on a horizontal plane strikes the plane at Q.the average velocity of the particle for its journey from p to Q is

Answer 1

A particle is projected with velocity u at an angle alpha from a point p on a horizontal plane strikes the plane at Q.the average velocity of the particle for its journey from p to Q is.....

solution : horizontal range, R = u²sin2α/g

and time of flight, T = 2usinα/g

we know, average velocity is the total displacement by total time taken.

or, v = ∆x/∆t

here, total displacement = horizontal range = R

and total time taken = Time of flight = T

so, average velocity = R/T

= {u²sin2α/g}{2usinα/g}

[here sin2α = 2sinα.cosα ]

so, average velocity = {2u²sinα.cosα/g}/{2usinα/g}

= ucosα

hence, average velocity of particle is ucosα