A projectile is shot from the edge of a cliff h = 245 m above ground level w/an initial speed of v0 = 125?

Question

Determine the time taken by the projectile to hit point P at ground level.

in seconds.

Determine the range X of the projectile as measured from the base of the cliff in km.

At the instant just before the projectile hits point P, find the horizontal and the vertical components of its velocity. (Take up and to the right as positive directions.) Horizonal/vertical.What is the the magnitude of the velocity?What is the angle made by the velocity vector with the horizontal?

° (below the horizontal)

Find the maximum height above the cliff top reached by the projectile.

in meters.

Answer 1

We need to know the angle that the canon fired the projectile. Having the velocity only is not sufficient. Because the last part of the question asks for a maximum height , it it logical that the projectile was not fired horizontally, but at some angle to the horizontal, upwards. Without this piece of information, we cannot do this problem.

Answer 2

Hi, sorry wish I could actually work it all out for u but im busy studying myself atm lol but I would feel bad if I left without giving any help. But take in mind ive only done projectile motion involving throwing off ground so this is probly all wrong if theres a difference (im assuming there is)

- Determine the time taken by the projectile to hit point P at ground level in seconds..

Ok so you know the initial velocity correct? (im assuming this is the vertical vector initial velocity if not you need to work that out doubt it is really.) Now when you get the initial vertical velocity you know that the final will be 0  hence use kinematic equation vf = vi + at  (remember a = -10/-9.8ms^-2) Now when you work out t itll actually be half the time as youve calculated the time for it to reach max height which in projectile is half the total time so times t by 2

- Determine the range X of the projectile as measured from the base of the cliff in km.

Ok so you now have t so range is pretty much d(range) = horizontal velocity times time

you'll need to calculate the horizontal velocity

At the instant just before the projectile hits point P, find the horizontal and the vertical components of its velocity. (Take up and to the right as positive directions.) Horizonal/vertical.What is the the magnitude of the velocity?What is the angle made by the velocity vector with the horizontal?

° (below the horizontal)

Find the maximum height above the cliff top reached by the projectile.

in meters.