KE and PE word Problem Practice1. The Royal Gorge Bridge is situated 321m above the Arkansas River in Colorado. IF the GPE
associated with a tourist on the bridge is 1.73 x 105J with respect to the river, what is the tourist’s
mass?
2. The most massive piece of equipment ever carried by a plane was a 1.24x105kg generator built in
Germany in 1993. How far above the ground was the generator when the PE associated with it
was 9.17x108J?
3. With an elevation of 5334m above sea level, the village of Aucanquilca, Chile is the highest
inhabited town in the world. What would be the GPE associated with a 64kg person in
Aucanquilca?
4. The largest land predator is the male polar bear; which typically has a mass of around 500 kg. If
the maximum KE for a polar bear with this mass is 6,050 J, what is its top speed?
5. The KE of a golf ball is measured to be 143.3J. If the golf ball has the mass of about 47g, what is
its speed?
6. Although slow on land, the leatherback turtle has the record for the fastest water speed of any
reptile: 9.87m/s. It is also among the largest of reptiles. If its KE is 6080J what is its mass?
7. A cheetah can run briefly with a speed of 31m/s. Suppose a cheetah with a mass of 47kg runs at
this speed. What is the cheetah’s kinetic energy?
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KE and PE word Problem Practice1. The Royal Gorge Bridge is situated 321m above the Arkansas River in Colorado. IF the GPE
associated with a tourist on the bridge is 1.73 x 105J with respect to the river, what is the tourist’s
mass?
GPE = M●G●H
Givens:
1.73 x 105 J = M (9.8 m/s2) (321 m)
h = 321m
PE = 173,000 J
1.73 x 105 J = M (3146)
m=?
M (3146) = 1.73 x 105 J
M(3146)
M=
1
3146
1
3146
= 1.73 x 105 J
173,000 J
1.73 x 105 J
=
3146
3146
=
55.0 kg
2. The most massive piece of equipment ever carried by a plane was a 1.24x105kg generator built in
Germany in 1993. How far above the ground was the generator when the PE associated with it
was 9.17x108J?
Givens:
GPE = M●G●H
h=?
PE = 9.17 x 108 J
9.17 x 108 J
9.17 x 108 9.17 x 102
917
GPE
m = 1.24 x105kg
H=
=
=
=
=
= 758 m
5
2
6
1.24 x10 kg ● 9.8 m/s
1.21 x10
1.21
1.21
M●G
Givens:
h = 5334 m
PE = ?
m = 64 kg
3. With an elevation of 5334m above sea level, the village of Aucanquilca, Chile is the highest
inhabited town in the world. What would be the GPE associated with a 64kg person in
Aucanquilca?
GPE = M●G●H = (64 kg) (9.8 m/s2) (5334 m) = 3.345 x 106 J
= 3,345,000 J
4. The largest land predator is the male polar bear; which typically has a mass of around 500 kg. If
the maximum KE for a polar bear with this mass is 6050 J, what is its top speed?
Givens:
v=?
KE = 6050 J
m = 500 kg
V =
2 KE
=
M
2 (6050 J)
500 kg
=
12,100 J
500 kg
=
24.2 =
4.92 m/s
5. The KE of a golf ball is measured to be 143.3J. If the golf ball has the mass of about 47g, what is
Givens:
its speed?
v=?
V =
KE = 143.3 J
m = 47 g = 0.047 kg
2 KE
=
M
2 (143.3 J)
=
.047 kg
286.6 J
.047 kg
=
6098 =
78 m/s
6. Although slow on land, the leatherback turtle has the record for the fastest water speed of any
reptile: 9.87m/s. It is also among the largest of reptiles. If its KE is 6080J what is its mass?
Givens:
v = 9.87 m/s
KE = 6080 J
m=?
V =
2 KE
V2
=
2 (6080 J)
9.87 x 9.87
=
12,160 J
97.4 /s
=
124.8 kg
7. A cheetah can run briefly with a speed of 31m/s. Suppose a cheetah with a mass of 47kg runs at
this speed. What is the cheetah’s kinetic energy?
22,583.5 J
Givens:
v = 31 m/s
KE = ?
m = 47 kg
KE = 0.5 x m x v2 = 0.5 x 47 kg x (31 m/s)2 = 0.5 x 47 x 961 = 22,583.5 J
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