The precision (relative error) of the centripetal force is 1%.
<h3>Relative error</h3>
This is the error in measurement of a variable obtained in comparison with other variables.
F = mv²/r
where;
- F is centripetal force
- m is mass 
- v is velocity
- r is radius
F/m = v²/r
F/m = (0.01v)²/(0.01r)
F/m = 0.01v²/r
F/m = 1%(v²/r)
Thus, the precision (relative error) of the centripetal force is 1%.
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Answer:
L2 = 1.1994 m
the length of the pendulum rod when the temperature drops to 0.0°C is 1.1994 m
Explanation:
Given;
Initial length L1 = 1.2m
Initial temperature T1 = 27°C
Final temperature T2 = 0.0°C
Linear expansion coefficient of brass x = 1.9 × 10^-5 /°C
The change i length ∆L;
∆L = L2 - L1
L2 = L1 + ∆L ...........1
∆L = xL1(∆T)
∆L = xL1(T2 - T1) ......2
Substituting the given values into equation 2;
∆L = 1.9 × 10^-5 /°C × 1.2m × (0 - 27)
∆L = 1.9 × 10^-5 /°C × 1.2m × (- 27)
∆L = -6.156 × 10^-4 m
From equation 1;
L2 = L1 + ∆L
Substituting the values;
L2 = 1.2 m + (- 6.156 × 10^-4 m)
L2 = 1.2 m - 6.156 × 10^-4 m
L2 = 1.1993844 m
L2 = 1.1994 m
the length of the pendulum rod when the temperature drops to 0.0°C is 1.1994 m
 
 
        
             
        
        
        
The gravitational force between Mars and the Sun is 
Explanation:
The magnitude of the gravitational force between two objects is given by  the equation:
 
where
 is the gravitational constant
 is the gravitational constant
m1, m2 are the masses of the two objects
r is the separation between them
In this problem, we have:
 is the mass of the Sun
 is the mass of the Sun
 is the mass of Mars
 is the mass of Mars
 is the average distance Mars-Sun
 is the average distance Mars-Sun
Substituting into the equation, we find the gravitational force:

So, the closest answer is

Learn more about gravitational force:
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Answer:
The change in momentum = -20000 kg m/s.
Explanation:
Mass m = 1000 kg
speed v₁ = 20 m/s
speed v₂ = 0 m/s
We know that,
The change in momentum
ΔP = m (Δv)
ΔP = m (v₂ - v₁)
      = 1000 (0 - 20)
      = 1000 (-20)
      = -20000 kg m/s
Thus, the change in momentum = -20000 kg m/s.
Note: negative sign indicates that the velocity is reducing when it hits the barrier.
 
        
             
        
        
        
1) The heat added to system
2) 800J
3) I'm not sure but I think it would be 300J.. Not certain tho