Answer:
I
Explanation:
vector quantities always have spedd and direction
The correct answer is: Velocity
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:

Explanation:
Given:
- Distance from the shore,

- distance of house from the shore,

- speed of rowing,

- speed of walking,

<em>For the least amount of time to reach the house one must row at the nearest point on the shore and then walk from there.</em>
<u>Now the time taken to reach the shore:</u>


<u>Time taken in walking to house from the shore:</u>




<u>Therefore total time taken:</u>


We can use the formula of motion in physics (2nd law od newton) in this problem:
x direction: Fsin ∅ = ma
y direction: Fcos ∅ -mg = 0
∅ is equal to sin ∅ / cos ∅ or x/y
tan ∅ = ma / mg = a /g
Applying acceleration formula:
v = vo + at ; 28 = 0 + 6a ; a = 4.67 m/s^2
∅ = tan-1 (a/g) = tan-1 (4.67/9.81) = <span>25.4 degrees.</span>