1.
Round off the following number to three significant figures (a) 58, 342 m,
(b) 68, 534, (c) 2, 553 N, (d) 7,555 kg
Solution:
2. Wood has a density of 4.70 slug/ft3. What is its density expressed in SI units?
Solution:
3. Represent each of the ff. combinations of units in the correct SI form using an
appropriate prefix: (a) kN/µN, (b) Mg/mN and (c) MN/(kg.ms).
Solution:
4. Represent each of the ff. combinations of in the correct SI form (a) m/ms, (b)
µ/km, (c)ks/mg, and (d) km.µN.
Solution:
5. Represent each of the ff. quantities in the correct SI form using an appropriate
prefix: (a) 0.000 431 kg, (b) 35.3(103) N, and (c) 0.005 32 km.
Solution:
6. If a car is travelling at 55mi/h, determine its speed in km/h and m/s.
Solution:
7. The pascal (Pa) is actually a very small unit of pressure. To show this convert
1Pa= 1N/m2 to lb/ft2. Atmospheric pressure at sea level is 14.7 lb/in2. How
many pascals is this?
Solution:
8. The specific weight (wt/vol) of brass is 520 lb/ft3. Determine its density (m/v)
in SI units. Use an appropriate prefix.
Solution:
9. A rocket has a mass of 250(103) slugs on earth. Specify (a) its mass in SI units
and (b) its weight in SI units. If the rocket is on the moon, where the
acceleration due to gravity is gm= 5.30ft/s2, determine to three significant
figures (c) its weight in SI units and (d) its mass in SI units.
Solution:
10. Evaluate each of the ff. to three significant figures and express each answer
in SI units using an appropriate prefix: (a) 0.631Mm/(8.60 kg)2
(b) (35(103m)2/48kg3.
Solution:
11. Evaluate each of the ff. to three significant figures and express each answer
in SI units using an appropriate prefix: (a) 354 mg. 45(45km)/0.0356kN, (b)
(0.004 53 Mg)(201 ms), and (c) 435 MN/23.2 mm.
Solution:
12. Convert each of the ff. and express the answer using an appropriate prefix:
(a) 175 lb/ft3 to kN/m3, (b) 6ft/h to mm/s, and (c) 835 lb.ft to kN.m.
Solution:
13. Convert each of the ff. to three significant figures: (a) 20 lb.ft to N.m,
(b) 450 lb/ft3 to kN/m3, and (c) 15 ft/h to mm/s.
Solution:
14. Evaluate each of the ff. and express with an appropriate prefix: (a) (430kg) 2
(c) (0.002 mg)2, and (c)(230m)3
Solution:
15. Determine the mass of an object that has a weight of (a) 20 mN, (b) 150kN,
and (c) 60MN. Express the answer to three significant figures.
Solution:
16. What is the weight in newtons of an object that has a mass of: (a) 10 kg, (b)
0.5 g and (c) 4.50 Mg? Express the result to three significant figures. Use an
appropriate prefix.
Solution:
17. If an object has a mass 40 slugs, determine its mass in kg.
Solution:
18. Using the SI system of units, show that Eq 1-2 is a dimensionally
homogenous equation which gives F in newtons. Determine to three
significant the gravitational force acting bet. Two spheres that are touching
each other. The mass of each sphere is 200 kg and the radius is 300 mm.
Solution:
19. Water has a density of 1.94 slug/ft3. What is the density expressed in SI units?
Express the answer to three significant figures.
Solution:
20. Two particles have a mass of 8 kg and 12 kg, respectively. If they are 800
mm apart, determine the force of gravity acting between them. Compare the
results with the weight of each particle.
Solution:
21. If a man 155 lb on earth, specify (a) his mass in slugs (b) his mass in kg and
(c) his weight in newtons. If the man is on the moon, where the acceleration
due to gravity is gm = 5.30 ft/s2, determine (d) his weight in pounds, and
(e) his mass in kg.
Solution:
