Answer:
Principal focus of a concave mirror. The principal focus of a concave mirror is a point on its principal axis to which all the light rays are parallel and close to the axis converge after reflection from the concave mirror.
Focal length of a concave mirror. The focal length of a concave mirror is the distance between its pole and the principal focus
The reflecting surface of a spherical mirror forms a part of a sphere. The centre of this sphere. This point is called the centre of curvature of the spherical mirror. Center of curvature can also be defined as the point in the centre of the sphere from which the mirror was sliced. It is represented by the letter C. Please note that the centre of curvature lies outside the mirror's reflecting surface. The centre of curvature of a concave mirror lies in front of it. However, it lies behind the mirror in case of a convex mirror.
If a concave mirror were thought of as being a slice of a sphere, then there would be a line passing through the center of the sphere and attaching to the mirror in the exact center of the mirror. This line is known as the principal axis.
Answer:
0.14
Explanation:
Flow rate is the volume flowing through a point at a particular time, in calcuing flow rate we have
Q= v*t
it in terms of Area, we have Q= A*v
Where A= area
v= velocity.
Solving the question , flow rate is constant then
A*v= constant
A(i) v(i)= A(f) v(f)
Where A(i)= initial area= 1.00cm^2
A(f)= final area= 0.400cm^2
V(i) and V(f) are the initial and final velocity respectively and the ratio of the two will gives us the factor
Substitute the values into the equation we have
1 V(i)= 4 V(f)
But we were told that the cross sectional area of 1.00cm^2 branches into 18 smaller arteries.
Then
1 V(i)=0.4 V(f)*(18)
1 V(i)=7.2V(f)
Then if we find the ratio of the velocity, we will get the factor.
V(f)/V(i)= 1/7.2
V(f)/V(i)=0.14
Hence, the factor of the average velocity of the blood reduced when it passes into these branches is 0.14
Answer:

Explanation:
In this case we have to use the Principle of conservation of Momentum:
<em>This principle says that in a system the total momentum is constant if no external forces act in the system. The formula is:</em>

<em>Where:</em>
Mass of the first object.
Mass of the second object.
Initial velocity of the first object.
Initial velocity of the second object.
Final velocity of the first object.
Final velocity of the second object.
In <u>this problem</u> we have:


Observation:
Is because the system has the same initial velocity.
First we have to find
,

We can rewrite it as:

Replacing with the data:

We found the final velocity of the cart, but the problem asks for the resulting change in the cart speed, this means:

Then, the resulting change in the cart speed is:

34. The element would have 34 protons. Also 34 electrons.