LifePac Grade 12 Physics: Unit 3 Test 1203 Exam
Questions and Correct
1. energy correct answer: ability to do work
2. potential energy correct answer: energy in a stretched spring
3. geothermal energy correct answer: energy from steam within the earth
4. first law of thermodynamics correct answer: the thermodynamic equivalent of
conservation of energy
5. plasma state correct answer: form of matter in the highest energy state
6. liquid state correct answer: definite volume, no definite shape
7. solid state correct answer: definite volume, definite shape
8. temperature correct answer: average motion of molecules
9. heat energy correct answer: internal energy transferable from a warm body to a cool one
10. kinetic energy correct answer: energy by reason of motion
11. total energy =
KE + PE E= 1/2mv^2
+ mgh
1/2(2 kg)(10 mpsec)^2 + (2 kg) (9.8 mpsec.^2) (50 m)
= 1,080 J correct answer: Calculate the total energy of a 2-kg object moving at 10 m/sec 50 meters
above the surface.
12. PE = KE
mgh = 1/2mv^2
(5 sl) (32 ftpsec^2) (100 ft) = 1/2 (5 sl) v^2
v^2= 2(3,200) ft^2persec.^2 = 6,400 ft^2 / sec^2
v= 80 ft/sec correct answer: An object of mass 5 slugs is dropped form a height of 100 feet. With
what speed does it hit the ground? Hint correct answer: use the value of g in the English system.
13. P= E/t = mgh/t
(500 kg) (9.8 mpsec^2) (20 m) / 10 sec.
= 9,800 watts correct answer: A 500-kg elevator is raised to a height of 20 m in 10 seconds.
Calculate the power of the motor.
14. IMA= 30 ft/ 2 ft = 15
AMA= 500 lb/ 50 lb = 10
efficiency= AMA/IMA x 100%
efficiency= 10/15 x 100% = 66 2/3% correct answer: A pulley system lifts a 500-lb. block
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Questions and Correct
1. energy correct answer: ability to do work
2. potential energy correct answer: energy in a stretched spring
3. geothermal energy correct answer: energy from steam within the earth
4. first law of thermodynamics correct answer: the thermodynamic equivalent of
conservation of energy
5. plasma state correct answer: form of matter in the highest energy state
6. liquid state correct answer: definite volume, no definite shape
7. solid state correct answer: definite volume, definite shape
8. temperature correct answer: average motion of molecules
9. heat energy correct answer: internal energy transferable from a warm body to a cool one
10. kinetic energy correct answer: energy by reason of motion
11. total energy =
KE + PE E= 1/2mv^2
+ mgh
1/2(2 kg)(10 mpsec)^2 + (2 kg) (9.8 mpsec.^2) (50 m)
= 1,080 J correct answer: Calculate the total energy of a 2-kg object moving at 10 m/sec 50 meters
above the surface.
12. PE = KE
mgh = 1/2mv^2
(5 sl) (32 ftpsec^2) (100 ft) = 1/2 (5 sl) v^2
v^2= 2(3,200) ft^2persec.^2 = 6,400 ft^2 / sec^2
v= 80 ft/sec correct answer: An object of mass 5 slugs is dropped form a height of 100 feet. With
what speed does it hit the ground? Hint correct answer: use the value of g in the English system.
13. P= E/t = mgh/t
(500 kg) (9.8 mpsec^2) (20 m) / 10 sec.
= 9,800 watts correct answer: A 500-kg elevator is raised to a height of 20 m in 10 seconds.
Calculate the power of the motor.
14. IMA= 30 ft/ 2 ft = 15
AMA= 500 lb/ 50 lb = 10
efficiency= AMA/IMA x 100%
efficiency= 10/15 x 100% = 66 2/3% correct answer: A pulley system lifts a 500-lb. block
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