Posted by Charlie on Saturday, March 29, 2008 at 4:47pm.
A cannon shoots a shell straight up. It reaches its maximum height, 837 feet, and splits into two pieces, one weighing 2 lb and the other 5 lb. The two pieces are observed to strike the ground simultaneously. The 5 lb piece hits the ground 1,564 feet away from the explosion (measured along the x axis). Find the magnitude of the momentum of the 5 kg piece just before it strikes the ground.

Physics  bobpursley, Saturday, March 29, 2008 at 6:18pm
How long did it take to fall?
t=sqrt(2d/g)
What was the horizontal momentum:
momentum=mass(1564/time)
Now find the vertical momentum, and add them as vectors.

Physics  drwls, Saturday, March 29, 2008 at 6:21pm
Since they arrive at the same time, no vertical momentum is imparted by the explosion. Use the vertical distance that the 5 lb piece travels down from 837 ft, and the horizontal distance of 1564 ft, to get its horizontal velocity. Since momentum is conserved, the 2 lb piece acquires 2.5 times the horizontal velocity of the 5 lb piece but in the opposite direction. The vertical velocity component when it hits the ground is sqrt (2 g * 837 ft).
Use the vertical and horizontal components of V to get the megnitude.

Physics  Damon, Saturday, March 29, 2008 at 6:26pm
It is falling from 837 feet
Do the vertical problem first
v = 32 t
d = 837 = (1/2) a t^2 = 16 t^2
so t^2 = 52.3
t = 7.23 seconds
v at ground = 32 (7.23) = 231 ft/s
now call horizontal speed u
u is constant because there is no force in the horizontal direction
so speed = distance/time
u = 1564 ft/7.23 seconds = 216 ft/s
magnitude of speed = sqrt (u^2 + v^2) = sqrt (216^2 + 231^2) = sqrt(46795+53568)
= 316 ft/s
multiply that by the mass to get magnitude of momentum
Now I am not clear about the mass of this piece, 5 pounds or 5 kilograms
if it is five pounds use 5/32 for mass in slugs
Answer This Question
Related Questions
 Physics  A cannon shoots a shell straight up. It reaches its maximum height, 1,...
 Physics  A cannon shoots a shell straight up. It reaches its maximum height, 1...
 physics  A battleship simultaneously fires two shells toward two identical ...
 algebra  a 3 1/2 foot piece of rope is cut into two pieces. one of these pieces...
 Physics  17. A shell having a mass of 25kg is fired horizontally eastward from ...
 physics  17. A shell having a mass of 25kg is fired horizontally eastward from ...
 Algebra  99 inch pipe is cut into two pieces. One is two times the length of ...
 physics  A stone is thrown straight up from the ground with an initial speed of...
 math  A wire 320 in. long is cut into two pieces. One piece is formed into a ...
 physics  A basketball explodes into three separate pieces. Two pieces of equal ...
More Related Questions