Explanation:
At a height of 93 m, the gravitational potential energy is given by :
P = mgh
Where, m is the mass of a penny
We can find its mass.

We need to find how much potential energy will have transformed into kinetic energy at the half way point (46.5m). It can be calculated as :

Hence, a penny will have transferred 1.499 J of potential energy into kinetic energy.
Answer:
<h2>
t = 2.35s</h2>
Explanation:
Using one of the equation of motion expressed as v = u+at where;
v is the final velocity = 2.0m/s
u is the initial velocity = 25m/s
a is the acceleration = -a (since the acceleration is negative)
t is the time taken
Substituting the given parameters into the formula above;
2.0 = 25-9.81t
subtract 25 from both sides
2.0 - 25 = 25-9.81t - 25
-23 = -9.81t
Divide both sides by -9.81
-23/-9.81 = -9.81t/-9.81
t = 23.0/9.81
t = 2.35s
<em>Hence it took the car 2.35s to slow to a final velocity of 2.0 m/s</em>