Answer:
117.6 m/s downward
Explanation:
The penny is moving with uniform accelerated motion (free fall motion), so we can find its vertical velocity at time t with the following suvat equation:
v = u + at
where
v is the velocity at time t
u is the initial velocity
a is the acceleration
The penny starts at rest, so
u = 0
Also, the acceleration is the acceleration of gravity,
[tex]a=g=-9.8 m/s^2[/tex]
where we have chosen upward as positive direction, so the acceleration is negative, since it is downward.
Substituting t = 12 s, we find the velocity of the penny when it hits the ground:
[tex]v=0 + (-9.8)(12)=-117.6 m/s[/tex]
downward, since the sign is negative.
