and closing
.
The heart has 4 valves. They are what makes the lub-dub lub-dub sounds that can be heard from the chest.
The mitral valve is located between the left atrium and the left ventricle. It closes the left atrium to collect oxygenated blood from the lungs and opens to pass it on to the left ventricle.
The tricuspid valve is located between the right atrium and the right ventricle. It closes the right atrium to hold unoxygenated blood and opens to pass it on to the right ventricle ensuring a one way flow.
The aortic valve is located between the aorta and the left ventricle. It closes the left ventricle and opens to the aorta to pass on the oxygen-rich blood to the body.
The pulmonary valve is located between the pulmonary artery and the right ventricle. It closes off the right ventricle and opens to pass on unoxygenated blood to the lungs.
Answer:

Explanation:
From the Question We are told that
Initial Force 
Final Force 
Distance between the front and rear wheels \triangle x=3.20 m
Since

Therefore


Generally the equation for The center of mass is at x_2 is mathematically
given by




Answer:
t=40s,
Explanation:
If you can swim in still water at 0.5m/s, the shortest time it would take you to swim from bank to bank across a 20m wide river, if the water flows downstream at a rate of 1.5m/s, is most nearly:
from the question the swimmer will have a velocity which is equal to the sum of the speed of the water and the velocity to swi across the bank
Vt=v1+v2
the time is takes to swim across the bank will be
DY=Dv*t
DY=distance across the bank
Dv=ther velocity of the swimmer across the bank
t=20/ 0.5m/s,
t=40s, time it takes to swim across the bank
velocity is the rate of displacement
displacement is distance covered in a specific direction
Answer:
This is likely possible for a region whose matter density is higher than the normal average.
Explanation:
A galaxy is a collection of lumps in space which are clumped together and interact with each other. There are a lot of speculations on how galaxies were birthed. some believe its formed by a collection of massive gas, dust which eventually collapsed under their own gravitational pull. others says its formed by the combination of large lumps of matter which accumulated forming thee galaxies. The possibility of a galaxy forming is dependent on how massive the matter in the region of the universe is.
Wind creat by rain, rain created by water, water created from pee