1-) Write the following measurements with only 3 significant figures:
a-) 624.45 cm
b-) 7.546 g
c-) 76.58 s
d-) 65.445 m
2-) A train travels by recording the time intervals below between stations:
from A to B: 4.83 h
from B to C: 6.50 h
from C to D: 0.982 h
from D to E: 4 h
Correctly express the time the train takes:
a-) to go from A to C
b-) to go from B to D
c-) on the total route
d-) write the result of item a-) in non-decimal form (in h min s).
3-) Perform the indicated operations:
a-) 57.68 cm + 6.672 cm - 8.7 cm =
b-) 627.50 m²: 1.20 m =
c-) 0.48 m x 825.3 m =
d-) 321.785 m + 254.7 cm - 0.270 km =
e-) (2.045x103) m .(2.35x102) m =
4-) The mass of the Sun is about 1.99x1030 kg. The mass of the hydrogen atom, the main constituent of the Sun, is 1.67x10-27 kg. How many hydrogen atoms are there in the Sun? What is the order of magnitude of this result?
5-) A prism-shaped solid has volume V = 18.60 m³ and base area S = 2.25 m². Remembering that V = S.h, determine your height h in meters.
6-) A triangle has a base of 192.81 cm and a height of 8.9 cm. Calculate your area and represent the result with the correct number of S. F..
7-) The value of the electrical force between two charges, Q1 and Q2, is given by the expression:
If Q1 = 8.20x10-6 C, Q2 = 3.87x10-6 C, d = 1.45x10-2 m and k = 9.0x109 N.m2 /C² , calculate the magnitude of the electric force and express the result using significant figures .
8-) The measurement of the length of a pencil was performed by a student using a ruler graduated in mm. Of the alternatives presented, the one that correctly expresses the measure obtained is: (justify your choice)
a-) 15 cm
b-) 150 mm
c-) 15.00 cm
d-) 15.0 cm
e-) 150.00 mm
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