Question

Identical cannonballs are fired with the same force, one each from four cannons having respective bore lengths of 1.0 meter, 2.0 meters, 2.5 meters and 3.0 meters. Which cannon will have the minimum impulse on the ball if the force acting on the ball increases with the length of the bore?

Answer 1

wait you just now said same force.. so!??..

Answer 2

A. 3.0
B. 1.0
C. 2.5
D. 2.0

Answer 3

Meters*

Answer 4

Same force different distance

Answer 5

but in the question its mentioned that the force increases with distance!?

Answer 6

they are different cannon's, they might have the same force, but they don't tells us the weight of the ball.

Answer 7

and the bore lengths are different, so that is why they have different distances

Answer 8

i get the distance.. but i don't get the force part.. why is it mentioned that the force is the same??? and then the force increases?? :-/..

Answer 9

I'm not sure im trying to figure out the answer....

Answer 10

do you know the answer?

Answer 11

nope.. m trying to figure out the question lol :P

Answer 12

impulse = change in momentum!..

all balls will have definitely same initial momentum = zero

so its a question of which one has the least final momentum.. since force keeps on increasing.. the acceleration keeps increasing.. and since all balls have exactly the same mass, the one which goes the highest distance ends up being accelerated a lot.. and thus ends up having the highest momentum.. so the one with shortest length would have smallest momentum..

thus i think it should be the one with smallest length!

Answer 13

You were right! Thank You! very much appreciated :)

Answer 14

ah no problem ;-)!