Answer:
The valves prevent the backward flow of blood. These valves are actual flaps that are located on each end of the two ventricles (lower chambers of the heart). They act as one-way inlets of blood on one side of a ventricle and one-way outlets of blood on the other side of a ventricle.
Explanation:
Answer:

Explanation:
This is a projectile motion problem. We will first separate the motion into x- and y-components, apply the equations of kinematics separately, then we will combine them to find the initial velocity.
The initial velocity is in the x-direction, and there is no acceleration in the x-direction.
On the other hand, there no initial velocity in the y-component, so the arrow is basically in free-fall.
Applying the equations of kinematics in the x-direction gives

For the y-direction gives

Combining both equation yields the y_component of the final velocity

Since we know the angle between the x- and y-components of the final velocity, which is 180° - 2.8° = 177.2°, we can calculate the initial velocity.

Answer:
The magnitude of the hiker’s displacement is 2.96 km
Explanation:
Let the initial displacement of the hiker, = x = 2km
the final displacement of the hiker, = y = 1.4 km
The resultant of the two vectors, According to Pythagorean theorem is the vector sum of the two vectors.
R' = x' + y'
Check the image uploaded for solution;
It is hammer because hammers are not examples of a simple machine