Question 6 (10 points) The Washington Monument in our nation's capital is 555 ft high. Neglecting the effects of air resistance, what would be the
speed of the penny as it "hit" the ground?
оа
Ob
Oc
Od
48.3 m/s
-68.4 m/s
84.7 m/s
-57.6 m/s

a= g = - 9.81 m/s2.

The following equations will be helpful:

a = (vf - vo)/td = vot + 1/2 at2vf2 = vo2 + 2ad

When you substitute the specific acceleration due to gravity (g), the equations are as follows:

g = (vf - vo)/td = vot + 1/2 gt2vf2 = vo2 + 2gd

If the object is dropped from rest, the initial velocity ("vi") is zero. This further simplifies the equations to these:

g = vf /td = 1/2 gt2vf2 = 2gd

The sign convention that we will use for direction is this: "down" is the negative direction. If you are given a velocity such as -5.0 m/s, we will assume that the direction of the velocity vector is down. Also if you are told that an object falls with a velocity of 5.0 m/s, you would substitute -5.0 m/s in your equations. The sign convention would also apply to the acceleration due to gravity as shown above. The direction of the acceleration vector is down (-9.81 m/s2) because the gravitational force causing the acceleration is directed downward.

hope this info helps you out!