57.8k views
1 vote
Use the definition of scalar product, a with arrow · b with arrow = ab cos θ, and the fact that a with arrow · b with arrow = axbx + ayby + azbz to calculate the angle between the two vectors given by a with arrow = 5.0i hat + 5.0j + 4.0k and b with arrow = 6.0i hat + 3.0j + 5.0k.

2 Answers

5 votes

Final answer:

To find the angle between vectors â and ëb, compute their scalar (dot) product and magnitudes, then use the formula cos θ = (â · ëb) / (A × B) and find the inverse cosine of the result.

Step-by-step explanation:

To calculate the angle between two vectors â and ëb using their scalar components, first compute the scalar product (dot product) of the vectors, and then find the magnitudes of each vector. The dot product of vectors â and ëb is given by â · ëb = axbx + ayby + azbz, where ax, ay, az and bx, by, bz are the respective components of vectors â and ëb.

For vectors â = 5.0î + 5.0ơ + 4.0âk and ëb = 6.0î + 3.0ơ + 5.0âk, the dot product is:

â · ëb = (5.0)(6.0) + (5.0)(3.0) + (4.0)(5.0) = 30 + 15 + 20 = 65

To find the magnitudes of vector â and ëb we use the formula A = √(ax² + ay² + az²) and similar for B. For â this is A = √(5.0² + 5.0² + 4.0²) = √(25 + 25 + 16) = √66 and for ëb it is B = √(6.0² + 3.0² + 5.0²) = √(36 + 9 + 25) = √70.

Substituting the dot product and the magnitudes into the equation for cos θ, we have cos θ = â · ëb / (A × B), so cos θ = 65 / (√66 × √70). Finally, the angle between the vectors is obtained by taking the inverse cosine of this expression, θ = cos⁻¹(65 / (√66 × √70)).

User Iunfixit
by
5.3k points
1 vote

Answer:

5+5=10

4+6=10

angle between is 45

User Milkypostman
by
5.6k points