Find the magnitude |a| of the vector a = (−2, 8, −9).
Vectors: dot & cross product worksheet with answers
1.Easy
a = (−2, 8, −9)
|a| =
2.Easy
Find the x-component ûx of the unit vector û that points in the direction of a = (4, 7, 7).
a = (4, 7, 7)
ûx =
3.Medium
A constant force F = (5, −15, −15) N acts on an object while it moves in a straight line from point A(4, −2, −3) to point B(0, −4, 1). Coordinates are in metres. Find the work W done by the force.
F = (5, −15, −15) NA(4, −2, −3) mB(0, −4, 1) m
W = J
4.Medium
A constant force F = (20, 25, 20) N acts on an object while it moves in a straight line from point A(−1, −4, −2) to point B(3, −3, 3). Coordinates are in metres. Find the work W done by the force.
F = (20, 25, 20) NA(−1, −4, −2) mB(3, −3, 3) m
W = J
5.Hard
Find the area A of the parallelogram spanned by a = (−3, 5, 0) and b = (4, −6, 3).
a = (−3, 5, 0)b = (4, −6, 3)
A =
6.Hard
Find the area A of the parallelogram spanned by a = (−1, −6, −5) and b = (−3, −3, 3).
a = (−1, −6, −5)b = (−3, −3, 3)
A =
Answer key
- 1. |a| = 12.21
- 2. ûx = 0.3746
- 3. W = −50 J
- 4. W = 205 J
- 5. A = 17.61
- 6. A = 40.47
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