Applied Maths Help?

Cian_

Just looking for a bit of help with an applied maths question.

A ball is kicked from a point P on level ground. It hits the ground for the first time 27m from P after 3 seconds. During it's flight, the ball just passed over a vertical wall standing 5.4m from P.
Find:
i) The horizontal and vertical components of the initial velocity of the ball
ii) the height of the wall
iii) the speed of the ball as it passed over the wall.

decisions

What book, page, question? I may have it done somewhere.

Cian_

decisions wrote: »

What book, page, question? I may have it done somewhere.

Book is Fundamental Applied Mathematics 2nd Edition by Folens. Pg 46 Q 10.

decisions

Don't have it done, but I'm going to take a quick stab at it.

decisions

Throw up the answers.

aarond280

for part (i) let sx=27 (t=3) find ux, let sy=0 when t=3
for part (ii) let sx=5.4, t=0.6, out this into sy equation, sy=7.056
for part (iii) find vy and vx when t=0.6

decisions

(i) let ux= usina and uy = ucosa, then use t=3 and s=ut..... to get expressions for u and solve.

(ii) t when sy=5.4 and sub in to sx=uxt.....

(iii) vx,vy when t=expression from (ii) and get magnitude.

Cian_

aarond280 wrote: »

for part (i) let sx=27 (t=3) find ux, let sy=0 when t=3
for part (ii) let sx=5.4, t=0.6, out this into sy equation, sy=7.056
for part (iii) find vy and vx when t=0.6

where did you get t=0.6 for part 2?

Yakuza

See my post in the Maths forum, I've thrown up some pointers there.

aarond280

Cian_ wrote: »

where did you get t=0.6 for part 2?

If you let sx=5.4=9t, 5.4/9=t, t=0.6