A 5 gram coin is which is initially at rest is dropped from the observation deck
ID: 1777808 • Letter: A
Question
A 5 gram coin is which is initially at rest is dropped from the observation deck of a skyscraper 300 meters above the street below.
What is the work done by gravity on the coin as it falls? Joules
Because there is air resistance the coin was slowed and hit the ground with a final velocity of 50 m/s. What is the kinetic energy of the coin at this speed? Joules
How much work was lost to air resistance as the coin fell? Joules
What is the average force exerted on the coin due to the air resistance as it fell?
Explanation / Answer
Here,
mass of coin , m = 0.005 Kg
h = 300 m
work done by gravity on the coin = m *g * h
work done by gravity on the coin = 0.005 * 9.8 * 300
work done by gravity on the coin = 14.7 J
----------------------
kinetic energy of the coin = 0.50 * m * v^2
kinetic energy of the coin = 0.50 * 0.005 * 50^2
kinetic energy of the coin = 6.25 J
-------------------------------
work lost to air resistance = 14.7 - 6.25
work lost to air resistance = 8.45 J
the work lost to air resistance is 8.45 J
--------------------------------------
for the average force to fell
F * 300 = 8.45
F = 0.0281 N
the force needed is 0.0281 N
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.