Projectile Motion (1 Viewer)

[rawker]

There's a heap of questions... fairly similar. I'll give you the first

A lifeboat is dropped from a plane moving at 140m/s from a height of 110.5 m
-initial velocity of the projectile
-its initial horixontal veloctiy
-its initial vertical velocity
-its range
-its final horizontal velocity
-its final vertical velocity
-its final velocity
-the time taken to fall
-the height from which it was thrown
-its velocity 3 secs after droping
-its height 5 seconds after dropping

Could someone please answer that... if you use a formula state it, but if its just like initial velocity u=140, then dont worry.
thank you so much

 

[helper]

Yep, and all from Surfing Physics.
The first three you should be able to do yourself.

Do the time of flight next, using delta y =u_yt + o.5a_yt²

Then calculate range with this time and u_x, similar for final velocities, after finding horizontal and vertical, add them using pythagoras and find the angle with trig

 

[exa_boi87]

Ill make the assumption that the set of questions is rather generic due to a couple of reasons ..

1) They ask for the height after they tell you
2) They ask for position after 5 seconds (work out why thats so odd with the formula helper provided)

Post back if you're after worked solutions

 

[simbim21]

a) 140m/s
b)140m/s
c) 0
d) R=ut
use s=ut+1/2at(sqrd) to get t., then sub into R=ut (u=140m/s)
:.R=664.83m
e)140m/s
f) v=u+at
:.v= 46.55
g) find resultant of 46.55 and 140 (horizontal comp. is constant)
:.v= 147.5m/s at 18.39degrees to the horizontal
h)t=4.75 sec
i) 110.5m (stupid)
j) v=u+at
= 29.4 m/s
k) stupid again: doesnt work out (use s=ut+1/2atsqrd) the thing isnt even in the air for 5seconds.