Kinetic Energy and Work Presentation 2022

Work and Energy
Please use bold blue color of your fonts as
input/answer to the following conceptual, math
and problem solving questions.
Several animations/simulations are to be used in
order to arrive at the final answers.
Please check your answers, and when ready save
your work to be uploaded in Canvas.
Let’s proceed.
KINETIC ENERGY AND WORK
Which one of the objects has the GREATEST kinetic energy?
A. Cement Truck driving at 35 mph
B. Baseball thrown at 80 mph
C. Space Shuttle at launch
D. Not enough info to decide
This is because the mass of space shuttle is significantly greater than
baseball and cement truck. Also, its velocity at the time of launch is also
immensely greater than 80mph since it has to escape gravity.
Which one of the objects has the GREATEST Kinetic Energy?
Which has the least?
Calculate, show your work and answer here with the math that supports your
answer.
Pull the data from the table below and show your math that decides the answer.
Object Mass Speed
Baseball 0.15
kg
40 m/s (90 MPH)
Golf ball 0.05
kg
90 m/s (200
MPH)
Tennis 0.06 70 m/s (160
1
Objectives:
 To introduce
the concept of
work, kinetic
and potential
energy
 To explain the
motion of
objects using
the
Work/Energy

Ball kg MPH)
Baseball:
K E= 1
2 m v2
K E= 1
2 ( 0.15 kg ) (40 m
s )2
K E=120 J
Golf ball:
K E= 1
2 m v2
K E= 1
2 ( 0.05 kg ) ( 90 m
s )
2
K E=202.5 J ∨203 J
Tennis ball:
K E= 1
2 m v2
K E= 1
2 ( 0.06 kg ) ( 70 m
s )
2
K E=147 J
Golf ball has the GREATEST Kinetic Energy of 203 J and
Baseball has the LEAST Kinetic Energy of 120 J based on
above calculations.
2

B
.A
1.0 m
POTENTIAL ENERGY AND WORK
The figure shows a 2.0 Kg block of slippery cheese that slides along a frictionless
track from point A to point B. The cheese travels through a total distance of 2.0
m along the track, and a net vertical distance of 1.0 m.
What is the change in Potential Energy as the cheese slides from point A to point
B? Is it losing PE or gaining?
Remember to show your work that leads to the final numerical value.
Mass of the cheese block = 2kg
Height at point A = 1m
Acceleration due to gravity (g) = 9.8m/s2
Hence, potential energy at point A = 2*9.8*1 = 19.6 J
Height at point B = 0m
The mass of cheese block and acceleration due to gravity
would remain the same.
Hence, potential energy at point B = 2*9.8*0 = 0 J
The change in potential energy as cheese block moves from
point A to point B is 19.6 J. There is a decrease in potential
energy as cheese moves from point A to point B.
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