The density of the fluid is 776.3 
<u>Explanation:</u>
Buoyant force is the upward pushing force whenever an object is trying to get immersed in fluid. So this is the force given by the fluid on the object which is trying to get immersed. The buoyant force is found to be directly proportional to the product of density of the object, volume of the object. And here the acceleration due to gravity will be acting as proportionality constant.

As, buoyant force is given as 671 N and volume is 0.0882
and acceleration is known as 9.8 m/
. Then density is

Thus,

Density is 776.3 kg
.
Answer:
The speed decreases.
Explanation:
This can be explained using the conservation of linear momentum.
Since there is no friction, the initial moment of the train must be equal to its linear moment after it is filled with water.
the initial linear momentum is

where
is the initial mass of the train, and
the initial speed of the train.
And linear momentum after the water filled the train car is

where
is mass of the train after the rain, and
the speed of the train after the rain
<u>the equality must be fulfilled:</u>

We know that if water is added to the train,
that is the mass after the water is added, is greater than
which is the mass of the train without the water.
Therefore, in order for the conservation of the linear momentum to be fulfilled: 
the speed after the water is added (
) must be smaller than the initial train speed (
) . So the speed of the car decreases.
Answer:
If x₁=12 cm then k=1.7985 N/m
If x₂=15 cm then k=1.4388 N/m
Explanation:
Hanging mass= 22 g=0.022 kg
Acceleration due to gravity g=9.81 m/s²
If x₁=displacement= 12 cm=0.12 m
k= spring constant


∴k = 1.7985 N/m
If x₂=15 cm=0.15 m
Force of the hanging mass is same however the spring constant will change

∴k = 1.4388 N/m
As the mass is not changing the spring constant has to change. That means that here there are two spring one with k=1.7985 N/m and the other with k= 1.4388 N/m
A magnetic domain is a group of atoms aligns with magnetic poles. Domains are usually <span>light and dark stripes visible within each grain.</span>