The precipitate is the barium sulfate, or 3) BaSO4. This is because it is a solid (as seen by the (s)), unlike the other aqueous product. The fact that it is a solid means that it is insoluble in water and therefore a precipitate.
Hope this helps!
It's a homogeneous mixture
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Answer:
The measured redshift is z =2
Explanation:
Since the object is traveling near light speed, since v/c = 0.8, then we have to use a redshift formula for relativistic speeds.

Finding the redshift.
We can prepare the formula by dividing by lightspeed inside the square root to both numerator and denominator to get

Replacing the given information


Thus the measured redshift is z = 2.
Answer:
The velocity of the skateboard is 0.774 m/s.
Explanation:
Given that,
The spring constant of the spring, k = 3086 N/m
The spring is stretched 18 cm or 0.18 m
Mass of the student, m = 100 kg
Potential energy of the spring, 
To find,
The velocity of the car.
Solution,
It is a case of conservation of energy. The total energy of the system remains conserved. So,






v = 0.774 m/s
So, the velocity of the skateboard is 0.774 m/s.