Answer:
In terms of distance, average speed is 20 km/h
In terms of displacement, average speed is 0 km/h.
Explanation:
Total distance:

Total time is 3.0 hours
but:

In terms of distance.
substitute:


In terms of displacement:

Impulse is a force acting briefly on a body and producing a finite change of momentum.
This relates to momentum because impulse is a change in momentum. Impulse = momentum. Since force is a vector quantity, impulse is also a vector in the same direction. Impulse applied to an object produces equivalent vector change in its linear momentum, also in the same direction. m•(triangle)v
The density of the object is approximately 1.91 kg per m³.
42 kg is a measure of mass, and 22 m³ is a measure of volume. Knowing this, you can use the relationship

to solve for the object's density.
42 kg

22 m³

1.91 kg per m³.