Answer:
Step-by-step explanation:
1. Use of lubricants
Lubricants like oil and grease helps to decrease friction by forming a thin film in between different parts of the machine. This film covers up the scratches and bumps on the surfaces of different parts. This reduces interlocking between the two surfaces. Thus reducing the friction.
2. Use ball bearings
Two moving surfaces in a machine are attached by placing small steel balls or steel rollers in between them. This way, the moving parts avoid direct contact and the force of sliding friction turns into rolling friction. Rolling friction is less than sliding friction, in doing so reducing the friction.
3. Polishing
Polishing reduces the unevenness of a surface. This will reduce interlocking between the surfaces.
4. Streamlining
Streamlining is the process where you make a machine in a shape that avoids air and water resistance. This reduces friction because a streamlined object cuts through the water and air molecules.
250/360 = x/60
x = 41.7 cm
This is because when the whole circle is 250 cm (angle is 360 degrees), 60 degrees means that the arc is 41.7 cm.
Explanation:
The square base of the pyramid has four sides with length 15 inches, making its perimeter four times that, or 60 inches. The slant height is
112×60=90 inches.
Therefore, the area of the base is B=152=225 square inches.
Each of the four lateral triangles has area 12⋅15⋅90=675 square inches.
The total surface area is 225+4⋅675=2,925 square inches.
Answer:
x = 40 1/2
Step-by-step explanation:
The hash marks tell you the triangles are similar and the smaller one is 1/2 the size of the larger one. Then x is half the length of the corresponding segment marked 81.
x = 81/2
x = 40 1/2
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You may have to write it as 81/2 or as 40.5. Sometimes the answer needs to be in a particular form.
Answer:
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