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2 years ago

Find a vector length of 5m in the xy plane that is perpendicular to A=3i+6j+2k hint use dot product

Physics

1 answer:

forsale [732]2 years ago

6 0

Answer:

Explanation:

vector A =(3i^+4J^-2k^),

let the required vector is B = x i^ + y j^

sqrt (x2 + y2) = 5,

x2 + y2 = 25 ..............(1)

Since vector A and B are perpendicular to each other then,

A.B = 0

3x + 4 y = 0

y = -3x/4 ..............(2)

Solving these two equations we get x = 4 and y = -3;

hence vector B = 4 i^ -3 j^

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Sound with a frequency of 1250 Hz leaves a room through a doorway with a width of 1.05 m.At what minimum angle relative to the c

kiruha [24]

Answer:

15.19°, 31.61°, 51.84°

Explanation:

We need to fin the angle for m=1,2,3

We know that the expression for wavelenght is,

$\lambda = \frac{c}{f}$

Substituting,

$\lambda = \frac{344}{1250}$

$\lambda = 0.2752m$

Once we have the wavelenght we can find the angle by the equation of the single slit difraction,

$sin\theta = \frac{m \lambda}{W}$

Where,

W is the width

m is the integer

$\lambda$ the wavelenght

Re-arrange the expression,

$\theta = sin^{-1} \frac{m\lambda}{W}$

For m=1,

$\theta = sin^{-1} \frac{1 (0.2752)}{1.05}= 15.19\°$

For m=2,

$\theta = sin^{-1} \frac{2 (0.2752)}{1.05}= 31.61\°$

For m=3,

$\theta = sin^{-1} \frac{3 (0.2752)}{1.05}= 51.84\°$

The angle of diffraction is directly proportional to the size of the wavelength.

5 0

3 years ago

Lord Beckett and members of the EIT Co. spot the Black Pearl in the distance making its way towards land. As a

KATRIN_1 [288]

Answer:

Explanation:

The cannonball goes a horizontal distance of 275 m . It travels a vertical distance of 100 m

Time taken to cover vertical distance = t ,

Initial velocity u = 0

distance s = 100 m

acceleration a = 9.8 m /s²

s = ut + 1/2 g t²

100 = .5 x 9.8 x t²

t = 4.51 s

During this time it travels horizontally also uniformly so

horizontal velocity Vx = horizontal displacement / time

= 275 / 4.51 = 60.97 m /s

Vertical velocity Vy

Vy = u + gt

= 0 + 9.8 x 4.51

= 44.2 m /s

Resultant velocity

V = √ ( 44.2² + 60.97² )

= √ ( 1953.64 + 3717.34 )

= 75.3 m /s

Angle with horizontal Ф

TanФ = Vy / Vx

= 44.2 / 60.97

= .725

Ф = 36⁰ .

6 0

2 years ago

9. Pick the best example of Newton's Second Law in action.

madreJ [45]

Answer:

A rocket taking off from earth which pushes gasses in one direction and the rocket in

the other

7 0

3 years ago

If a 20 g cannonball is shot from a 5 kg cannon with a velocity of 100

balu736 [363]

Strange as it may seem, the statement in the question appears to be TRUE.

-- Before the shot, neither the cannon nor the ball is moving, so their combined momentum is zero.

-- Since momentum is conserved, we know immediately that their combined momentum AFTER the shot also has to be zero.

-- (20g is rather puny for a "cannonball" ... about the same weight as four nickels. But we'll take your word for it and just do the Math and the Physics.)

-- Momentum = (mass) x (velocity)

After the shot, the momentum of the cannonball is

(0.02 kg) x (100 m/s ==> that way)

Momentum of the ball = 2 kg-m/s ==> that way.

-- In order for both of them to add up to zero, the momentum of the cannon must be (2 kg-m/s this way <==) .

Momentum of cannon = (5 kg) x (V m/s this way <==)

2 kg-m/s this way <== = (5 kg) x (V m/s this way <==)

Divide each side by (5 kg):

V m/s = (2/5) m/s this way <==

Speed of recoil of the cannon = -- 0.4 m/s

3 0

3 years ago

Help me with this???

Vikentia [17]

Yo sup??

Average velocity=total distance covered/total time taken

total distance covered=4 + 8=12 miles

total time taken=6 hours

Therefore

average velocity=12/6

=2 miles/hour

Hope this helps

8 0

3 years ago

Find a vector length of 5m in the xy plane that is perpendicular to A=3i+6j+2k hint use dot product​

Find a vector length of 5m in the xy plane that is perpendicular to A=3i+6j+2k hint use dot product