A projectile of mass M, initially at rest, is acted upon by a net force [including gravity] that increases linearly with time as the projectile accelerates in a vertical gun barrel of length L,
Fy = bt (1)
where b is a constant. After leaving the gun barrel, the time-dependent force vanishes and
the projectile rises under gravitational acceleration to a maximum height h above the end of
the barrel.
L
h
(a) How long does it take the projectile to reach the top end of the gun barrel? Please
express your answer in terms of b, L, and M.
(b) How fast is the projectile moving as it exits the barrel? Please express your answer in
terms of b, L, and M.
(c) What is the mass M of the projectile in terms of b, L, g, and h?