__author__ = "jeffrey"
__date__ = "$2015/7/13 下午 01:43:26$"

__all__ = ['Projectile']

class Projectile(object):
    def __init__(self, mass, velocity):
        self.mass = mass
        self.velocity = velocity
aa720d9363a5f79d365ca6bfc3df3504370d5c7e
<mask token>

<mask token>


class Projectile(object):
    <mask token>

<mask token>


class Projectile(object):

    def __init__(self, mass, velocity):
        self.mass = mass
        self.velocity = velocity

__author__ = 'jeffrey'
__date__ = '$2015/7/13 下午 01:43:26$'
__all__ = ['Projectile']


class Projectile(object):

    def __init__(self, mass, velocity):
        self.mass = mass
        self.velocity = velocity

__author__ = "jeffrey"
__date__ = "$2015/7/13 下午 01:43:26$"

__all__ = ['Projectile']

class Projectile(object):
    def __init__(self, mass, velocity):
        self.mass = mass
        self.velocity = velocity