Homework SourseCalculate the force of gravity on earth of an object that h
. Calculate the force of gravity on earth of an object that has a mass of 200 kg. A. 1,962 N B. 20 N C. 326 N D. 123 N
2. Estimate in pounds the mass of a 780-kg shipment. A. 860 lb B. 78 lb C. 1,720 lb D. 354 lb
3. The force on an area 16 m by 12 m is 24,000 N. What is the pressure per square meter? (Note: This question requires two calculations.) A. 364 Pa B. 501 Pa C. 857 Pa D. 125 Pa
4. If a gas tank is labeled with a capacity of 70 liters, how many U.S. gallons will it hold? (Note: There are four quarts in one gallon.) Round off your answer to the nearest tenth. A. 61.6 gal B. 18.5 gal C. 74.0 gal D. 15.4 gal
5. If you were to say that a material has 2,000 kg/m3 , you would be referring to its A. mass. B. density. C. volume. D. temperature.
6. A joule is used to measure A. pressure. B. torque. C. power. D. energy.
7. Convert 890 mm to centimeters. A. 8,900 cm B. 89 cm C. 8.9 cm D. 0.89 cm
8. The number of meters in 1 km is A. 1. B. 0.01. C. 100. D. 1,000.
9. Convert 26°C to degrees Fahrenheit. A. 104.4°F B. 112°F C. 76.6°F D. 78.8°F
10. Which one of the following SI units is used to measure current? A. Candela B. Watt C. Weber D. Ampere
11. Which one of the following measurements represents the longest distance? A. 1 km B. 50 mm C. 5 m D. 10 cm
12. On a construction site, the workers excavated 30,000 cubic feet of dirt. How many cubic meters did they excavate? A. 105 B. 1,050 C. 849 D. 84.9
13. The metric unit used to measure the distance from your home to your workplace is the A. kilometer. B. millimeter. C. meter. D. centimeter.
14. In SI, motor output is rated in A. horsepower. B. watts. C. kilowatts. D. foot-pounds per second.
15. Which one of the following symbols represents a unit smaller than a meter? A. dam B. cm C. km D. hm
16. If the dimensions of a room are 10 ft by 20 ft, what is its approximate area in square meters? A. 2152 m2 B. 9 m2 C. 200 m2 D. 18.58, or 19 m2
17. The unit 10 m is equivalent to A. 1 hm. B. 100 cm. C. 100 mm. D. 1 dam.
18. Convert 15 cg to milligrams. A. 150 mg B. 1.5 mg C. 0.15 mg D. 1,500 mg
19. If an object travels 400 m in 253 s, what is its speed in m/s? A. 20 m/s B. 12.2 m/s C. 1.58 m/s D. 13.1 m/s End of exam
20. The term used to measure a change in speed of an object is A. velocity. B. flow. C. capacity. D. acceleration
Solution
Answer 1. Force F = m x g we are given m = 200 kg and we know g = 9.81 m/s^2,
therefore F = 200 x 9.81 = 1962 N
Hence answer is A.
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Answer 2. Given mass = 780 kg
Since we know that, 1kg = 2.20462 pounds,
therefore 780 kg = 780 x 2.20462 pounds
= 1719.61 pounds
= 1720 pounds (approx)
Hence the correct answer is C.
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Answer 3. Given the force on an area 16 m by 12 m is 24,000 N
As we know, Pressure = Force / Area
Therefore, Pressure = 24000 /(16 x 12) = 125 N/m^2
Hence the correct answer is D.
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Answer 4. Given the Volume = 70 liters
We know 1 liter = 0.264172 U.S.gallons
hence 70 liters = 70 x 0.264172 U.S.gallons
= 18.492 U.S.gallons
= 18.5 U.S.gallons (approx)
Hence the correct answe is B.
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Answer 5. As we know that kg/m^3 is a unit to measure density so the correct answer is B.
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Answer 6. A joule is used to measure Energy and hence the correct answer is D.
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Answer 7. Since 10 mm = 1 cm therefore 890 mm = 890/10 cm = 89cm
hence the correct answer is B.
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Answer 8. The number of meters in 1 kilometer is 1000, hence the correct answer is D.
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Answer 9. We recall the relation between degree Celsius and degree Fahrenheit is given by the relation
F = C x (9/5) + 32
Hence F = 26 x(9/5) +32 = 78.8 degree C, therefore the correct anser is D.
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Answer 10. The SI unit of current is Ampere and hence the correct answer is D.
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Answer 11. Correct answer is 1 km so choice A.
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Answer 12. 1 cubic feet = 0.0283168 cubic meter
hence 30,000 cubic feet = 30000 x 0.0283168 = 849.50 cubic feet
therefore the correct answer is C.
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Answer 13. The metric unit used to measure the distance from your home to your workplace is kilometer
and hence the correct answer is A.
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Answer 14. In SI, motor output is rated in Watts (same as SI unit of power). Hence the correct answer is B.
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Answer 15. From the given choices only cm is the unit smaller than km. Hence the correct answer is B.
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Answer 16. 10 ft x 20 ft = 200 ft^2
1 ft^2 = 0.092903 m^2
Hence 200 ft^2 = 200 x 0.092903 m^2 = 18.58 m^2
Therefore the correct choice is D.
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Answer 17. 10 m = 1dam and hence the correct answer is D.
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Answer 18. 15 cg = 15 x 10 mg = 150 mg therefore the correct answer is A.
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Answer 19. If an object travels 400 m in 253 s then it\'s speed in m/s is equal to 1.58 m/s
. Therefore the correct answer is C. __________________________________________________________________________
Answer 20. The term used to measure a change in speed of an object is velocity therefore the correct
answer is A
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