Answer: Work W = 0
Explanation: Work W = F·s. Because rock does not move, s = 0 and
work done is zero.
The angles in the triangle are 91 degrees, 53 degrees and 36 degrees respectively.
<h3>What is the cosine rule?</h3>
From the cosine rule we know that;
c^2 = a^2 + b^2 - 2abcosC
Since;
a = 0.47 m
b = 0.62 m
c = 0.78 m
Then;
(0.78)^2 = (0.47)^2 + (0.62)^2 - 2(0.47 * 0.62)cosC
0.61 = 0.22 + 0.38 - 0.58 cosC
0.61 - ( 0.22 + 0.38) = - 0.58 cosC
0.01 = - 0.58 cosC
C = cos-1(0.01/-0.58)
C = 91 degrees
Using the sine rule;
b/Sin B = c/Sin C
0.62/sinB = 0.78/sin 91
0.62/Sin B = 0.78
B = sin-1 (0.62//0.78)
B = 53 degrees
Angle A is obtained from the sum of angles in a triangle;
180 - (91 + 53)
A = 36 degrees
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<h2>
Answer: The Systeme international (International System of Units
)</h2>
The International System of Units (SI) is used in almost every country in the world (<em>except Burma, Liberia and the United States</em>).
This system was created in 1960 by the 11th General Conference of Weights and Measures in France and is made up of seven basic units:
-Ampere (electric current)
-Kelvin (temperature)
-Second (time)
-Meter (length)
-Kilogram (mass)
-Candela (luminous intensity)
-Mol (amount of substance) *added to the system in 1971
Plus an unlimited number of derived units from the main ones.
Answer:
Derived units are derived from these 7 base units. Derived units are dependent on the base units and are not independent of each other. ... Mass has SI units of kg, distance is measured in m and t has the SI unit of second. Thus, SI unit of force is kg.