Air from the outside is:



a. warmed, dried and cleaned by the nose and mouth

b. cooled, dried and cleaned by the nose and mouth

c. cooled, moistened and cleaned by the nose and mouth

d. warmed, moistened and cleaned by the nose and mouth

no gravitational energy but kinetic energy

known data:

time=4,2s

earth's acceleration: 9.8m/s²

formulas needed:

t=v÷g

s=vt+(gt²)÷2

solution:

t=v÷g

4,2=v÷9,8

v=9,8×4,2

v=41,16m/s

s=vt+(gt²)÷2

s=41,16×4,2-9.8×(4,2)²÷2

s=86.436m

explanation :

distance is total path travelled by an object during its entire journey. it is a scalar quantity i.e only magnitude.

displacement is the shortest distance covered by an object. it is basically the change in position of object. it is a vector quantity i.e direction as well as magnitude.

when an object is travelling in a straight line and stops at the end point, then both distance and displacement are same.

when an object is travelling in a straight line and then changes its direction or we can say come backwards then the magnitude of distance and displacement are different.