A spring gun is made by compressing a spring in a tube and then latching the spring at

the compressed position. A 4.97-g pellet is placed against the compressed and latched
spring. The spring latches at a compression of 5 cm, and it takes a force of
9.12 N to compress the spring to that point.
(a) If the gun is �red vertically, how fast (m/s) is the pellet moving when it loses contact
with the spring?
(b) To what maximum height (m) will the pellet rise? (as measured from the original
latched position)

1 answer

The spring constant is
k = 9.12/0.05 = 182.5 N/m

Contact ceases when the compression is x = 0, when no more force is applied by the spring. At that time,

(1/2)kXo^2 = (1/2) m V^2

Xo is the latched compression, 0.05 m.

Solve for V. m must be in kilograms.

2) From the original latched position, add Xo to sqrt(Vo^2)/(2g)