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.
5.5 s
Explanation:
The time it takes for the ball to reach its maximum height can be calculated using

since
at the top of its trajectory. Plugging in the numbers,

When light passes from a faster medium into a slower medium, light will be refracted toward a line drawn perpendicular to the point of refraction. <em>(B)</em>
Answer:
L/D= 112
Explanation:
Aerodynamics can be defined as the branch of dynamics which deals with the motion of air, their properties and the interaction between the air and solid bodies.
Aerodynamics law explains how an airplane is able to fly. There are four forces of flight, and they are; lift, weight, thrust and drag. The amount of lift generated by a wing divided by the aerodynamic drag is known as the lift to drag ratio.
Lift increases proportionally to the square of the speed.
The solutions to the question is the file attached to this explanation.
Lift,L= qC(l). S---------------------------(1).
and,
Drag,D = qC(d).S ----------------------(2).
Hence, Lift to drag ratio,L/D= C(l)/C(d).
Therefore, we have to compute various angle of attack.(check attached file)...
Then, (L/D) will then be equal to 112.
Explanation:
Distance travelled = Area under the line
= ut + ½ (v-u)t
Acceleration (a) = (v-u)/t and so (v-u) = at
Therefore,
Distance travelled (s) = ut + ½ (v-u)t = ut + ½ (at)t = ut + ½ at²
Thus,proved.