Conservation of Energy on a Coaster
Ei=Ef if no work is done
Use the coaster below to answer the questions.
moves right. Assume no friction!
The coaster is released from rest at A and
A
E
B
20m
F
Mass of empty
coaster is 500kg
D 10m
C
What location/s has:
1) Greatest speed? ___________
2) Zero speed? ___________
3) Greatest kinetic energy? ___________
4) Least kinetic energy? ___________
5) Greatest potential energy? ___________
6) Kinetic energy equal to potential energy? ___________
7) Potential energy of zero? ___________
8) **(trick question) Where is the least total energy? __________________
9) Will the coaster make it over the second hill? [ yes / no]
10) Will the coaster stop at the top of the second hill? [ yes / no ] Explain your answers.
11) If the second hill is 25m, instead of 10m, will the coaster make it to the top? [ yes / no ]
Explain why.
12) If the first hill of a coaster is 30m and there are no frictional forces how high can the next
hill be so that the coaster comes to rest at the second peak?
General Physics
Wksh Energy (purple)
edited2/15/16
For the coaster on the front, calculate and give numerical answers.
At the top of the 20m hill:
13) What is the PE?
________
14) What is the KE?
________
15) What is the TME? ___________
At C, the bottom of the first hill:
16) What is the TME? ___________
18) What is the PE? ___________
17) What is the KE? ___________
19) What is the velocity? _________
Halfway down the first hill:
20) What is the TME? ___________
22) What is the PE? ___________
21) What is the KE? ___________
23) What is the velocity? __________
24) At the top of the second hill:
25) What is the TME? ___________
27) What is the PE? ___________
26) What is the KE? ___________
28) What is the velocity? _________
Compare the answers for 23 and 28. Explain why they are similar.
29) Energy is always conserved. In this class, we assume mechanical energy is conserved and no
energy is transferred to heat. But for real coaster calculations, mechanical energy is not
conserved. What other forms of energy are important for real coasters?
30) A coaster starts from rest atop a 35m high hill. The second hill is 20m.
a) What is the TE? __________
b) What is the KE at the top of the second hill? _________
c) What is the speed at the top of the second hill? _________
General Physics
Wksh Energy (purple)
edited2/15/16