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3 years ago

8

A runner starts at the start line runs around a 400 m track two times ending up back at the store now what is the runners distan

ce and displacement

1 answer:

Marta_Voda [28]3 years ago

7 0

Answer:

Distance is 800m and displacement is 0m

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this is my 5th time waisting my points for this question because I could fail my final and I am not getting any answers so can s

Neko [114]

Answer:

<em>The person needs to apply 25 N to balance the seesaw</em>

Explanation:

<u>Moment</u>

The moment of a force is a measure of its tendency to cause a body to rotate about a specific point or axis.

The moment M of a force F located at a distance x from the axis of rotation is calculated as follows:

M = F.x

The image shows a moment of M=100 N.m is needed to be applied to balance the seesaw. It can also be noted that the distance to the pivot is x=4 m

To calculate the force needed to balance the seesaw, we solve for F:

$\displaystyle F=\frac{M}{x}$

$\displaystyle F=\frac{100\ N.m}{4\ m}$

F = 25 N

The person needs to apply 25 N to balance the seesaw

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3 years ago

Which statement best defines an electric field?

dalvyx [7]

A region around a charged partical or object. Let me know if this works. Hope I could help you.

7 0

3 years ago

PtichkaEL [24]

Answer:

Densities increase down the group

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Softness increased going down the group

Speed of reacting increases going down the group

4 0

3 years ago

Find the resultant force of the following forces :

bezimeni [28]

The resultant of the given forces is; 6√2 N

<h3>How to find the resultant of forces</h3>

We are given the forces as;

10 N along the x-axis which is +10 N in the x-direction

6 N along the y-axis which is +6N in the y-direction

4 N along the negative x-axis which is -4N

Thus;

Resultant force in the x-direction is; 10 - 4 = 6N

Resultant force in the y-direction is; 6N

Thus;

Total resultant force = √(6² + 6²)

Total resultant force = 6√2 N

Read more about finding resultant of a force at; brainly.com/question/14626208

4 0

2 years ago

Read 2 more answers

The interior space of large box is kept at 30 C. The walls of the box are 3 m high and have a ‘sandwich’ construction consisting

White raven [17]

Answer:

$\frac{\dot Q}{A} =20.129\ W.m^{-2}$

$T_1=27.58\ ^{\circ}C$ & $T_2=2.41875\ ^{\circ}C$

Explanation:

Given:

interior temperature of box, $T_i=30^{\circ}C$

height of the walls of box, $h=3\ m$

thickness of each layer of bi-layered plywood, $x_p=1.25\ cm=0.0125\ m$

thermal conductivity of plywood, $k_p=0.104\ W.m^{-1}.K^{-1}$

thickness of sandwiched Styrofoam, $x_s=5\ cm=0.05\ m$

thermal conductivity of Styrofoam, $k_s=0.04\ W.m^{-1}.K^{-1}$

exterior temperature, $T_o=0^{\circ}C$

<u>From the Fourier's law of conduction:</u>

$\dot Q=\frac{dT}{(\frac{x}{kA}) }$

$\dot Q=\frac{dT}{R_{th} }$ ....................................(1)

<u>Now calculating the equivalent thermal resistance for conductivity using electrical analogy:</u>

$R_{th}=R_p+R_s+R_p$

$R_{th}=\frac{x_p}{k_p.A}+\frac{x_s}{k_s.A}+\frac{x_p}{k_p.A}$

$R_{th}=\frac{1}{A} (\frac{x_p}{k_p}+\frac{x_s}{k_s}+\frac{x_p}{k_p})$

$R_{th}=\frac{1}{A} (\frac{0.0125}{0.104}+\frac{0.05}{0.04}+\frac{0.0125}{0.104})$

$R_{th}=\frac{1.4904}{A}$ .....................(2)

Putting the value from (2) into (1):

$\dot Q=\frac{30-0}{\frac{1.4904}{A} }$

$\dot Q=\frac{30\ A}{1.4904}$

$\frac{\dot Q}{A} =20.129\ W.m^{-2}$ is the heat per unit area of the wall.

The heat flux remains constant because the area is constant.

<u>For plywood-Styrofoam interface from inside:</u>

$\frac{\dot Q}{A} =k_p.\frac{T_i-T_1}{x_p}$

$20.129=0.104\times \frac{30-T_1}{0.0125}$

$T_1=27.58\ ^{\circ}C$

&<u>For Styrofoam-plywood interface from inside:</u>

$\frac{\dot Q}{A} =k_s.\frac{T_1-T_2}{x_s}$

$20.129=0.04\times \frac{27.58-T_2}{0.05}$

$T_2=2.41875\ ^{\circ}C$

4 0

3 years ago