The part that causes the disc caliper piston to retract when the brakes are released is the square-cut O-ring.
The square cut seal is the most important part of a disc brake caliper, for keeping the brake behind the piston so that when you step on the brake pedal, it releases a pressure that applied to the piston which in return applies the pad to the rotor.
        
             
        
        
        
Answer:
The weight of the girl = 1045.86 kg/m³
Explanation:
Density: This can be defined as the ratio of the mass of a body to the volume of that body. The S.I unit of density is kg/m³.
From Archimedes principle,
R.d = Density of the person/Density of water = Weight of the person in air/Upthrust.
⇒ D₁/D₂ = W/U............................... Equation 1.
Where D₁ = Density of the person, D₂ = Density of water, W = Weight of the person in air, U = Upthrust in water.
Making D₁ the subject of the equation,
D₁ = D₂(W/U)................................... Equation 2
<em>Given: D₂ = 1000 kg/m³ , W = 509.45 N, U = lost in weight = weight in air - weight in water = 509.45 - 22.34 = 487.11 N</em>
<em>Substituting these values into equation 2</em>
D₁ = 1000(509.45/487.11)
D₁ = 1045.86 kg/m³
Thus the weight of the girl = 1045.86 kg/m³
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Answer:120 min
Explanation:
Given
Amanda  spent  of her time after school doing Home work
 of her time after school doing Home work
And  of her remaining  time riding her bike
 of her remaining  time riding her bike
It is given that she rode her bike for 45 minutes in a week 
Let t be the time after school 
therefore Amanda spend  in home work and
 in home work and   time is left
 time is left
From remaining  time she spends
 time she spends  time riding her bike
 time riding her bike 
therefore 
thus 
therefore time  spent on home work is 
 
        
             
        
        
        
Explanation:
Work done is given by the product of force and displacement.
Case 1,
1. A boy lifts a 2-newton box 0.8 meters.
W = 2 N × 0.8 m = 1.6 J
2. A boy lifts a 5-newton box 0.8 meters.
W = 5 N × 0.8 m = 4 J
3. A boy lifts a 8-newton box 0.2 meters.
W = 8 N × 0.2 m = 1.6 J
4. A boy lifts a 10-newton box 0.2 meters.
W = 10 N × 0.2 m = 2 J
Out of the four options, in option (2) ''A boy lifts a 5-newton box 0.8 meters'', the work done is 4 J. Hence, the greatest work done is 4 J. 
 
        
             
        
        
        
V = IR
I = V/R
I = 12/6
I = 2 amps