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A bird moves from point (1, -2, 3) to (4...

A bird moves from point `(1, -2, 3)` to `(4, 2, 3)`. If the speed of the bird id `10 m//s`, then the velocity of the bird is :-

A

`5 (hati-2hatj+3hatk)`

B

`5 (4hati+2hatj+3hatk)`

C

`0.6 hat(i)+0.8 hat(j)`

D

`6hat(i)+8hat(j)`

Text Solution

Verified by Experts

The correct Answer is:
D
`vec(v)=((4-1)hat(i)+(2+2)hat(j)+(3-3)hat(k))/sqrt(3^(2)+4^(2)+0^(2))=(3hati+4hatj)/5`
`vec(v)=|vec(v)|hat(v)=10((3hat(i)+4hatj)/5)=6hat(i)+8hat(j)`
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ALLEN -KINEMATICS-EXERCISE-01
  1. A bird moves from point (1, -2, 3) to (4, 2, 3). If the speed of the b...

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  2. A particle moves for 20 seconds with velocity 3m/s and then moves with...

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  3. a particle is moving in x-y-plane at 2 m//s along x-axis. 2 seconds la...

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  4. The velocity of a particle moving along x-axis is given as v=x^(2)-5x+...

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  5. The co-ordinates of a moving particle at any time t are given by x=ct^...

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  6. When a 2 kg car driven at 20 m//s on a level road is suddenly put into...

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  7. A particle has initial velocity of (3hat(i)+4hat(j)) m//s and a accele...

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  8. A body starts from rest and is uniformly accelerated is 30m//s . The d...

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  9. Let A, B, C, D be points on a vertical line such that AB = BC = CD. If...

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  10. A particle is projected vertically upwards and it reaches the maximum ...

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  11. A parachutist drops first freely from a plane for 10 s and then his p...

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  12. With what speed should a body be thrown upwards so that te distances t...

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  13. A particle is projected vertically upwards from a point A on the groun...

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  14. The velocity-time graph of a linear motion is shown in figure. The dis...

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  15. If an object is released in air, the magnitude of its acceleration wou...

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  16. Initially car A is 10.5 m ahead of car B. Both start moving at time t ...

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  17. A man moves in x-y plane along the path shown. At what points is his a...

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  18. Which of the following velocity-time graph shows a realistic situation...

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  19. The graph between the displacement x and time t for a particle moving ...

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  20. The velocity -time of a body falling from rest under gravity and rebou...

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