A runner completes the 200-meter dash with a time of 19.80 seconds. What was the runner's average speed in miles per hour?

Answer:

53.2

Explanation:

You can use the kinematic equation: displacement of x = (initial velocity + final velocity)*t/2

Subsititing: 17+21 = 38 * 2.8/2 = 53.2

Note: Displacement = distance between the 2 points

Answer:

1.5 * 10^-2 Tm^2

Explanation:

Electric Flux = B.A cos(theta)

B = 0.055 T

A = 0.32 m^2

theta = 30

Electric Flux = (0.055 T).(0.32 m^2).Cos(30) = 0.0152 = 1.5 * 10^-2 Tm^2

Answer:

Explanation:

Kinetic energy ( KE ) = 1/2 m v²

= m²v² / 2 m = p² / 2m where p is momentum

KE = p² / 2m

p² = 2m KE

KE is constant

p is proportional to mass

So car having higher mass will have higher momentum .

p₁ = √ ( 2 m x KE )

p₂ = √ ( 6 m x KE )

p₂ - p₁ =  √ ( 6 m x KE ) - √ ( 2 m x KE )

= √KE m ( √6 - √2 )

Kinetic energy ( K.E )

[tex]= \frac{1}{2} m v^2\\\\= \frac{m^2 v^2}{2 m} \\\\= \frac{p^2}{2m}[/tex]

where p is momentum

[tex]K.E =\frac{p^2}{2m}\\\\p^2 = 2m. KE[/tex]

KE is constant

p is proportional to mass

So car having higher mass will have higher momentum .  

[tex]p_1 =\sqrt{(2m*K.E)}\\\\p_2 = \sqrt{(6m*K.E)} \\\\p_2 - p_1 = \sqrt{(6m*K.E)} -\sqrt{(2M*K.E} \\\\p_2 - p_1 = \sqrt{K.E m(\sqrt{6}-\sqrt{2}) }[/tex]

The difference is shown above.

Learn more:

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Answer:

[tex]a=20.14\ m/s^2[/tex]

Explanation:

The time period of the simple pendulum is given by :

[tex]T=2\pi \sqrt{\dfrac{l}{g}}[/tex]

l is the length of the pendulum

g is the acceleration due to gravity

We have,

T = 1.4 s, l = 1 m

So,

[tex]T^2=\dfrac{4\pi^2 l}{g}\\\\g= \dfrac{4\pi^2 l}{T^2}\\\\g= \dfrac{4\pi^2 \times 1}{(1.4)^2}\\\\g=20.14\ m/s^2[/tex]

So, the acceleration due to gravity of that planet is [tex]20.14\ m/s^2[/tex].

Answer:

Distance, S = 440 meters.

Explanation:

Given the following data;

Initial velocity, u = 17m/s

Time, t = 20 seconds

Final velocity, v = 27m/s

To find the distance;

First of all, we would determine the acceleration of the truck.

Acceleration = (v-u)/t

Substituting the given values into the equation, we have;

Acceleration = (27 - 17)/20

Acceleration = 10/20

Acceleration = 0.5m/s²

Now, we would use the second equation of motion to find the distance traveled.

S = ut + ½at²

S = 17*20 + ½*0.5*20²

S = 340 + 0.25*400

S = 340 + 100

S = 440m

The equations of motion can be used to obtain the distance covered as 440 m.

We have to use of the equations that are used for uniformly accelerated motion in solving the problem. The chosen equation must be;

v^2 = u^2 + 2as and v = u + at

v = final velocity

u = initial velocity

a = acceleration

s = distance

To obtain the acceleration;

27 = 17 + 20(a)

27 - 17 = 20a

a = 0.5 ms-2

Now, to obtain the distance;

v^2 = u^2 + 2as

v^2 - u^2/as = s

s = (27)^2 - (17)^2/2(0.5)

s = 440 m

Learn more about the acceleration: https://brainly.com/question/12134554

Answer:

Option D. is correct.

Explanation:

The object's mechanical energy refers to the sum of the potential and kinetic energies of the object. When an object falls, its potential energy (PE) decreases, and its kinetic energy (KE) increases. The increase in kinetic energy is exactly equal to the decrease in potential energy.

Option D. is correct.

Answer:

Untrasound

Explanation:

Your welcome :)

Answer:

The balls velocity is 1 divided by 3

The velocity of the ball is 18.85 m/s.

The ball’s centripetal acceleration is 236.87 m/s².

The ball's centripetal force is  118.44 Newton.

Centripetal acceleration is a characteristic of an object's motion along a circular path. Centripetal acceleration applies to any item travelling in a circle with an acceleration vector pointing in the direction of the circle's center.

Given parameters:

length of the string: l = 1.5 meters.

Time interval = 60 seconds.

Total number of complete rotation = 120.

Hence, the velocity of the ball = 120×2π×1.5/60 m/s

= 18.85 m/s.

The ball’s centripetal acceleration = (velocity)²/ radius

= (18.85)²/1.5 m/s²

= 236.87 m/s²

The ball's centripetal force = mass × centripetal acceleration

= 0.5 × 236.87 Newton

= 118.44 Newton

Learn centripetal acceleration here:

https://brainly.com/question/14465119

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The answer is "Infrared"

Hope this helps

Answer:

x-rays

Explanation:

Answer:

Explanation:

individual and then net

hope that helps I could be wrong about this one though

Answer:

ΔV = - 3274 V

Explanation:

For this exercise we can use conservation of energy

starting point.

         Em₀ = U = q ΔV

final point

          Em_f = K = ½ m v²

energy is conserved

          Em₀ = Em_f

          q ΔV = ½ m v²

          ΔV = [tex]\frac{m \ v^2 }{q}[/tex]

let's calculate

          ΔV = [tex]\frac{4.4 \ 10^{-6} \ 80^2 }{ 2 \ 4.3 10^{-6} }[/tex]

          ΔV = 3274.4 1 V

since the charge q is negative, the potential at point B must be less than the potential at point A, so the answers

          ΔV = - 3274 V

Frequency = (speed) / (wavelength)

Frequency = (3 x 10⁸ m/s) / (124 x 10⁻⁹ m)

Frequency = 2.42 x 10¹⁵ Hz

Answer:

i). (a) in the same direction as , (d) lower

ii). (f) opposite the direction of, (g) higher

Explanation:

An proton may be defined as a sub atomic particle and it has a positive electrical charge. Its mass is slightly less than that of a neutron. When a proton is placed in an electrical field that is uniformly charged, it is at rest. When the proton first moves out from rest from the uniform electric field, it will move in a direction which is same as that of the electric field and it will move to a region of higher potential.

An electron is defined as the subatomic particle having negative electric charge. When an electron is released form rest from an uniform electric field, it will move in the opposite direction of the uniform electric field and will move to the region of lower electric potential.

Explanation:

1.

We use the equation

h = [tex]\frac{gt^2}{2}[/tex], where

h is the height traveled,

g is the acceleration due to gravity and

t is the time taken to reach height h.

We can now calculate t to be

[tex]\sqrt{\frac{2*1.2 m}{9.81 m/s^2} }[/tex]

= 0.495 s

Let v be the initial velocity of the player.

The player deaccelarates from v m/s to 0 m/s in 0.495 s at the rate of 9.81 m/s^2.

v = 9.81 m/s^2 x 0.495 s = 4.85 m/s

2.

The player takes 0.3 s to increase his velocity from 0 m/s to 4.85 m/s. So his average accelaration is

4.85 m/s / 0.3 s = 16.2 m/s^2

Time needed = t = 20.83 s

Given

car speed = 85 km/h

truck speed = 73 km/h

Required

the time it takes for the car to reach the truck

Solution

When the car reaches the truck, the distance between them will be the same

x car - 250 m = x truck

General formula for distance (d) :

d = v.t

So the equation becomes :

85t-250 = 73t

12t=250

t = 20.83 s

The maximum height : 81.63 m

Given

0.4 kg mass

vo = initial speed = 40 m/s

Required

the maximum height

Solution

We can use the law of conservation energy(ME=PE+KE) or use parabolic motion

For parabolic motion :

h max = (vo²sin²θ)/2g

θ = 90°(straight upward)

Input the value :

h max = (40²sin²90°)/2 x 9.8

h max = 81.63 m

Answer:

Speed of the melon = 0.25 m/s

we would normally don't see the melon moving due to friction with the resting surface.

Explanation:

We use conservation of momentum:

Pi = Pf

with Pi = 0.1 kg * 30 m/s = 3 kg m/s

and Pf = 0.1 kg * 20 m/s + 4.0 kg * V = 2 kg m/s + 4 * V

Then using the equality above, we solve for V (velocity of the melon)

3 kg m/s = 2 kg m/s + 4 V

1 kg m/s = 4 kg * V

Then V = 1 / 4  M/s = 0.25 m/s

So we would normally don't see the melon moving due to friction with the resting surface.

Explanation:

Moral duties are the duties performed by the people on the basis of humanity and moral values. The following are some of the moral duties :

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Answer:

[tex]4.77\ \text{A}[/tex]

Explanation:

F = Magnetic force = 4.11 N

[tex]I_n[/tex] = Net current

[tex]I_2[/tex] = Current in one of the wires = 7.68 A

B = Magnetic field = 0.59 T

[tex]\theta[/tex] = Angle between current and magnetic field = [tex]65^{\circ}[/tex]

[tex]l[/tex] = Length of wires = 2.64 m

[tex]I[/tex] = Current in the other wire

Magnetic force is given by

[tex]F=I_nlB\sin\theta\\\Rightarrow I_n=\dfrac{F}{lB\sin\theta}\\\Rightarrow I_n=\dfrac{4.11}{2.64\times 0.59 \sin65^{\circ}}\\\Rightarrow I_n=2.91\ \text{A}[/tex]

Net current is given by

[tex]I_n=I_2-I\\\Rightarrow I=I_2-I_n\\\Rightarrow I=7.68-2.91\\\Rightarrow I=4.77\ \text{A}[/tex]

The current I is [tex]4.77\ \text{A}[/tex].

Answer:

3. Fructose

Explanation:

Fructose is a sugar found naturally in fruits, fruit juices, some vegetables and honey.

it is number 3 (Fructose)

Answer:

7 would be C, a cell.

Explanation:

Hi.

7 would be C, a cell.

A cell is the basic unit of structure and function in all living things.

If it is living, it is made of cells.

Hope this helps.

Answer:

7. Cell

8. Organelle

Answer:

blue

Explanation:

nswer the following about two objects, A and B, whose motion produced ihe following ... "A" starts with a greater (t) position. Since they ... since you are moving away from the origin

Answer:

The time that passes until the police catch the speeder is 82.6204 seconds.

Explanation:

A body performs a uniformly accelerated rectilinear motion or uniformly varied rectilinear motion when its path is a straight line and its acceleration is constant. This implies that the speed increases or decreases its modulus in a uniform way.

The position is calculated by the expression:

x = x0 + v0*t + 1/2*a*t²

where:

First, let’s look at the police car’s equations of motion. In this case:

So: x = 50 m/s*t + 1/2*2 m/s²*t²

Now for the speeder’s car’s equations of motion you know:

So: x = 3,000 m + 55 m/s*t + 1/2*1 m/s²*t²

When the police catch the speeder they are both in the same position. So:

50 m/s*t + 1/2*2 m/s²*t²= 3,000 m + 55 m/s*t + 1/2*1 m/s²*t²

Solving:

0= 3,000 m + 55 m/s*t + 1/2*1 m/s²*t² - 50 m/s*t - 1/2*2 m/s²*t²

0= 3,000  + 55 *t + 1/2*t² - 50*t - 1*t²

0= 3,000  + 55 *t - 50*t - 1*t² + 1/2*t²

0= 3,000  + 5*t - 1/2*t²

Applying the quadratic formula:

[tex]x1,x2=\frac{-5+-\sqrt{5^{2}-4*(-\frac{1}{2})*3000 } }{2*(-\frac{1}{2} )}[/tex]

x1= -72.6209

and x2= 82.6209

Since you are calculating the value of a time and it cannot be negative, then the time that passes until the police catch the speeder is 82.6204 seconds.

Kinetic energy = mv²

Therfore kinetic energy =14175 joule

Answer:

Explanation:

Electrical current is the movement of charge. The units are Amperes (Amps)

Answer:

Explanation:

Force of friction = μ N , where μ is coefficient of friction , N is normal force on the body .

a )

Given,

Normal force N = 400 N

Force of friction = 300 N

μ = coefficient of static friction = ?

Putting the values ,

300 = 400 μ

μ = .75

b )

Normal force N = 400 N

Force of friction = 200 N

μ = coefficient of kinetic  friction = ?

Putting the values ,

200 = 400 μ

μ = .50

c ) see attached file .

Answer:

Explanation:

In order to have a period that matches the Earth's rotation, a satellite must be in a circular orbit, and 42,164 km from the center of the Earth.

But that's not quite enough to make sure that it always stays over the same point on the Earth's surface (and appears motionless in the sky). For that to happen, the satellite's orbit has to be directly over the Equator.

The Moon has nothing to do with any of this.

on smooth surface like mirror.