Find the magnitude |a| of the vector a = (−8, 2, 7).
Vectors: dot & cross product worksheet with answers
1.Easy
a = (−8, 2, 7)
|a| =
2.Easy
Find the magnitude |a| of the vector a = (−9, 7).
a = (−9, 7)
|a| =
3.Medium
Find the value of k for which the vectors a = (−1, 3, 4) and b = (k, −6, −1) are perpendicular.
a = (−1, 3, 4)b = (k, −6, −1)
k =
4.Medium
Find the dot product a·b of a = (−2, −4, −1) and b = (1, −7, 5).
a = (−2, −4, −1)b = (1, −7, 5)
a·b =
5.Hard
For a = (2, −3, 1) and b = (2, 0, −4), find the z-component (a × b)z of the cross product a × b.
a = (2, −3, 1)b = (2, 0, −4)
(a × b)z =
6.Hard
A force F = (60, −50, −40) N acts at point A(−3, 0, −2). Coordinates are in metres. Find the z-component Mz of the moment of the force about the origin O(0, 0, 0).
F = (60, −50, −40) NA(−3, 0, −2) mO(0, 0, 0) m
Mz = N·m
Answer key
- 1. |a| = 10.82
- 2. |a| = 11.4
- 3. k = −22
- 4. a·b = 21
- 5. (a × b)z = 6
- 6. Mz = 150 N·m
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