How many full length strands of hair are collected from the scalp to use as a sample?

A firecracker in a coconut blows the coconut into three pieces. Two pieces of equal mass fly off south and west, perpendicular t

Lisa [10]

Explanation:

Let us assume that piece 1 is $m_{1}$ is facing west side. And, piece 2 is $m_{2}$ facing south side.

Let $m_{1} \text{and} m_{2}$ = m and $m_{3}$ = 2m. Hence,

$2mv_{3y} = m(21)$

$v_{3y} = \frac{21}{2}$

= 10.5 m/s

$2mv_{3x} = m(21)$

$v_{3x} = \frac{21}{2}$

= 10.5 m/s

$v_{3} = \sqrt{v^{2}_{3x} + v^{2}_{3y}}$

= $\sqrt{(10.5)^{2} + (10.5)^{2}}$

= 14.84 m/s

or, = 15 m/s

Hence, the speed of the third piece is 15 m/s.

Now, we will find the angle as follows.

$\theta = tan^{-1} (\frac{v_{3y}}{v_{3x}})$

= $tan^{-1}(\frac{10.5}{10.5})$

= $tan^{-1} (45^{o})$

= $45^{o}$

Therefore, the direction of the third piece (degrees north of east) is north of east.

5 0

4 years ago

A mass with mass 4 is attached to a spring with spring constant 24 and a dashpot giving a damping 20. The mass is set in motion

aleksandrvk [35]

Answer: $x(t) = 14e^{-2t} - 10e^{-3t}$

Explanation: In a mass-spring-damper system, the differential equation that rules the motion of the mass is: mx" + cx' + kx = 0

Using m = 4, k = 24 and c = 20, we have

4x" + 20x' + 24x = 0

Simplifying, we have

x" + 5x'+ 6x = 0

The characteristic equation of this differential is

$r^{2} + 5r + 6 = 0$

The solutions for the quadratic equation are: $r_{1} = -2$ and $r_{2} = -3$

Hence:

x(t) = $C_{1}e^{-2t} + C_{2}e^{-3t}$

x'(t) = $-2C_{1}E^{-2t} - 3C_{2}e^{-3t}$

To determine the constants, we have the initial conditions x(0) = 4 and

x'(0) = 2, then:

$x(0) = C_{1} + C_{2} = 4\\ C_{1} = 4 - C_{2}$

$x'(0) = -2C_{1} -3C_{2} = 2\\-2(4-C_{2}) -3C_{2} = 2\\C_{2} = -10\\C_{1} = 4 - C_{2}\\C_{1} = 14$

Substituing the constants:

$x(t) = 14e^{-2t} - 10e^{-3t}$

The position function for this system is: $x(t) = 14e^{-2t} - 10e^{-3t}$

7 0

3 years ago

In the circuit diagram, what does the symbol made of two Long lines and two short lines with a positive and a negative sign at e

Licemer1 [7]

That symbol represents a source of DC, usually a battery.

The zig-zag line represents a resistor, and the two little circles
connected by a short line represent a switch in the closed position.,

8 0

3 years ago

A 25 N force pushes a block across a surface for 6 m.How much work is done by the applied force?

hram777 [196]

Answer: 150 joules

Explanation:

Force applied on a block = 25N

Distance moved by block = 6 m

Workdone = ?

Recall that work is done when force is applied on an object over a distance. And it is measured in joules.

I.e Workdone = Force X Distance

= 25N x 6 metres

= 150 joules

Thus, 150 joules of work is done by the applied force.

4 0

4 years ago

What is the value of coefficient of friction force

san4es73 [151]

Answer:

<h2>There is a frictional force between two objects that are not in relative motion. Such a force is called the static friction force.</h2><h2>There is a frictional force between two objects that are not in relative motion. Such a force is called the static friction force....</h2><h2>There is a frictional force between two objects that are not in relative motion. Such a force is called the static friction force....Friction coefficients.</h2><h2>There is a frictional force between two objects that are not in relative motion. Such a force is called the static friction force....Friction coefficients.MATERIAL S K</h2><h2>There is a frictional force between two objects that are not in relative motion. Such a force is called the static friction force....Friction coefficients.MATERIAL S KMetal on leather 0.6 0.5</h2><h2>There is a frictional force between two objects that are not in relative motion. Such a force is called the static friction force....Friction coefficients.MATERIAL S KMetal on leather 0.6 0.5Wood on leather 0.5 0.4</h2><h2>There is a frictional force between two objects that are not in relative motion. Such a force is called the static friction force....Friction coefficients.MATERIAL S KMetal on leather 0.6 0.5Wood on leather 0.5 0.4Rubber on concrete, dry 0.9 0.7</h2><h2>There is a frictional force between two objects that are not in relative motion. Such a force is called the static friction force....Friction coefficients.MATERIAL S KMetal on leather 0.6 0.5Wood on leather 0.5 0.4Rubber on concrete, dry 0.9 0.7wet 0.7 0.57</h2>

Explanation:

<h2>Greetings, I'm from my beloved Mexico</h2>

3 0

3 years ago

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