elpermic said:
(1) The formula calls for the angle between the two vectors. That angle is not 100°. (Draw a diagram.)elpermic said:
Scalar product, also known as dot product, is a mathematical operation that takes two vectors and returns a scalar quantity. It is calculated by multiplying the magnitude of the two vectors by the cosine of the angle between them.
Scalar product is a scalar quantity, meaning it has only magnitude and no direction. Vector product, on the other hand, is a vector quantity that has both magnitude and direction.
Scalar product is used in physics to calculate the work done by a force, or the component of a force in a certain direction. It is also used in calculating the angle between two vectors, and in finding the projection of one vector onto another.
Some common applications of scalar product include calculating the amount of force needed to move an object, determining the distance between two objects, and finding the angle of elevation or depression in trigonometry problems.
The scalar product can be used to derive the Law of Cosines, which is a fundamental trigonometric law used to find the length of a side or the measure of an angle in a triangle. It relates the lengths of the sides of a triangle to the cosine of one of its angles.