Advertisements
Advertisements
प्रश्न
Find all vectors of magnitude `10sqrt(3)` that are perpendicular to the plane of `hat"i" + 2hat"j" + hat"k"` and `-hat"i" + 3hat"j" + 4hat"k"`
उत्तर
Let `vec"a" = hat"i" + 2hat"j" + hat"k"` and `vec"b" = -hat"i" + 3hat"j" + 4hat"k"`.
Then `vec"a" xx vec"b" = |(hat"i", hat"j", hat"k"),(1, 2, 1),(-1, 3, 4)|`
= `hat"i"(8 - 3) - hat"j"(4 + 1) + hat"k"(3 + 2)`
= `5hat"i" - 5hat"j" + 5hat"k"`
⇒ `|vec"a" xx vec"b"| = sqrt((5)^2 + (-5)^2 + (5)^2)`
= `sqrt(3(5)^2)`
= `5sqrt(3)`
Therefore, unit vector perpendicular to the plane of `vec"a"` and `vec"b"` is given by
`(vec"a" xx vec"b")/|vec"a" xx vec"b"| = (5hat"i" - 5hat"j" + 5hat"k")/(5sqrt(3)`
Hence, vectors of magnitude of `10sqrt(3)` that are perpendicular to plane of `vec"a"` and `vec"b"` are `+-10sqrt(3) ((5hat"i" - 5hat"j" + 5hat"k")/(5sqrt(3)))`
i.e., `+- 10(hat"i" - hat"j" + hat"k")`.
APPEARS IN
संबंधित प्रश्न
Find a vector `veca` of magnitude `5sqrt2` , making an angle of `π/4` with x-axis, `π/2` with y-axis and an acute angle θ with z-axis.
Find `|veca| and |vecb|`, if `(veca + vecb).(veca -vecb) = 8 and |veca| = 8|vecb|.`
Find the magnitude of two vectors `veca and vecb`, having the same magnitude and such that the angle between them is 60° and their scalar product is `1/2`.
Find a vector of magnitude 5 units, and parallel to the resultant of the vectors `veca = 2i + 3hatj - hatk` and `vecb = hati - 2hatj + hatk`.
Represent the following graphically:
(i) a displacement of 40 km, 30° east of north
(ii) a displacement of 50 km south-east
(iii) a displacement of 70 km, 40° north of west.
If the sum of two unit vectors is a unit vector prove that the magnitude of their difference is `sqrt(3)`.
Find a vector of magnitude of 5 units parallel to the resultant of the vectors \[\vec{a} = 2 \hat{i} + 3 \hat{j} - \hat{k} \text{ and } \vec{b} = \hat{i} - 2 \hat{j} +\widehat{k} .\]
Find a vector \[\vec{r}\] of magnitude \[3\sqrt{2}\] units which makes an angle of \[\frac{\pi}{4}\] and \[\frac{\pi}{4}\] with y and z-axes respectively.
A vector \[\vec{r}\] is inclined at equal angles to the three axes. If the magnitude of \[\vec{r}\] is \[2\sqrt{3}\], find \[\vec{r}\].
Write the length (magnitude) of a vector whose projections on the coordinate axes are 12, 3 and 4 units.
Write two different vectors having same magnitude.
If in a ∆ABC, A = (0, 0), B = (3, 3 \[\sqrt{3}\]), C = (−3\[\sqrt{3}\], 3), then the vector of magnitude 2 \[\sqrt{2}\] units directed along AO, where O is the circumcentre of ∆ABC is
Prove that in a ∆ABC, `sin"A"/"a" = sin"B"/"b" = sin"C"/"c"`, where a, b, c represent the magnitudes of the sides opposite to vertices A, B, C, respectively.
The magnitude of the vector `6hat"i" + 2hat"j" + 3hat"k"` is ______.
A vector `vec"r"` is inclined at equal angles to the three axes. If the magnitude of `vec"r"` is `2sqrt(3)` units, find `vec"r"`.
Find a vector of magnitude 6, which is perpendicular to both the vectors `2hat"i" - hat"j" + 2hat"k"` and `4hat"i" - hat"j" + 3hat"k"`.
Prove that in any triangle ABC, cos A = `("b"^2 + "c"^2 - "a"^2)/(2"bc")`, where a, b, c are the magnitudes of the sides opposite to the vertices A, B, C, respectively.
The vector in the direction of the vector `hat"i" - 2hat"j" + 2hat"k"` that has magnitude 9 is ______.
The area under a velocity-time curve represents the change in ______?
Which of the following statements is false about forces/ couple?
Read the following passage and answer the questions given below:
|
Teams A, B, C went for playing a tug of war game. Teams A, B, C have attached a rope to a metal ring and is trying to pull the ring into their own area. Team A pulls with force F1 = `6hati + 0hatj kN`, Team B pulls with force F2 = `-4hati + 4hatj kN`, Team C pulls with force F3 = `-3hati - 3hatj kN`,
|
- What is the magnitude of the force of Team A ?
- Which team will win the game?
- Find the magnitude of the resultant force exerted by the teams.
OR
In what direction is the ring getting pulled?
Find a vector of magnitude 20 units parallel to the vector `2hati + 5hatj + 4hatk`.
