[Urgent] Help on Applications of the Physical World (1 Viewer)

[richz]

hey there,

im in need of urgent help for this question:

When a particle is fired in the open from a point O at a speed of 40m/s and at an angle A above the horizontal, where 0<A<pi/2, you may assume without proof that the horizontal displacement (x metres) and the vertical displacement (y m) of the particle from O at the time t seconds after firing are give by x = 40tcosA and y=40tsinA-5t^2. If the particle is fired with the same spd from a pt O on the floor of a horizontal tunnel of height 20 m, find the max horizontal range of the particle along the tunnel.

thnx

 

[velox]

??????????????????????????

 

[richz]

where A is between 0 and pi/2, you may assume without proof that the horizontal displacement (x metres) and the vertical displacement (y m) of the particle from O at the time t seconds after firing are give by x = 40tcosA and y=40tsinA-5t^2. If the particle is fired with the same spd from a pt O on the floor of a horizontal tunnel of height 20 m, find the max horizontal range of the particle along the tunnel.

 

[richz]

opps sorry for the spam i didnt know i couldnt use arrows

 

[richz]

ok here we are the q is up thnx in advance

 

[Estel]

For max range: solve for t when y=0 t=/0 and sub into x.

 

[richz]

i dont think thats rite

 

[Estel]

Upon reading your q, probably not: no way the particle can go through roof of tunnel.
meh
solve 20 = y then (allowing for fact it may never reach it, then proceed as above)