Find the z-component ûz of the unit vector û that points in the direction of a = (4, −7, −5).
Vectors: dot & cross product worksheet with answers
1.Easy
a = (4, −7, −5)
ûz =
2.Easy
Find the z-component ûz of the unit vector û that points in the direction of a = (−8, 0, 3).
a = (−8, 0, 3)
ûz =
3.Medium
A constant force F = (−30, −10, −10) N acts on an object while it moves in a straight line from point A(−2, −5, 1) to point B(4, −4, −3). Coordinates are in metres. Find the work W done by the force.
F = (−30, −10, −10) NA(−2, −5, 1) mB(4, −4, −3) m
W = J
4.Medium
Find the angle θ between the vectors a = (−2, −6, 4) and b = (−6, −5, 4), in degrees.
a = (−2, −6, 4)b = (−6, −5, 4)
θ = °
5.Hard
The unit vector n̂ is perpendicular to both a = (−3, 2, −2) and b = (2, 1, 5) and has a positive z-component. Find its y-component n̂y.
a = (−3, 2, −2)b = (2, 1, 5)n̂z > 0
n̂y =
6.Hard
The unit vector n̂ is perpendicular to both a = (4, −5, 1) and b = (3, 5, 1) and has a positive z-component. Find its y-component n̂y.
a = (4, −5, 1)b = (3, 5, 1)n̂z > 0
n̂y =
Answer key
- 1. ûz = −0.527
- 2. ûz = 0.3511
- 3. W = −150 J
- 4. θ = 27.96 °
- 5. n̂y = −0.6208
- 6. n̂y = −0.02746
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