PLEASE HELP!! Newton's second law of motion states that force equals mass times acceleration.
How would this law apply to a runner in a track and field event?

The runner needs to take a few steps to slow down after crossing the finish line.

To win the race, the runner must slow down on the turns and speed up on the straight sections.

The shoes of the runner help increase his mass so he can run faster.

Newton's second law of motion does not apply to track and field.

​

Answer:

(a) 9.28 m/s2

(b) 9.03 m/s2

(c) 9.8 m/s2

(d) 450 N, 670 N

Explanation:

mass of elevator + student, m = 870 kg

Reading of scale, R = 450 N

(a) When the elevator goes down, the weight decreases.

Let the acceleration is a.

By the Newton's second law

m g - R = m a

870 x 9.8 - 450 = 870 a

a = 9.28 m/s2

(b) R = 670 N

Let the acceleration is a.

870 x 9.8 - 670 = 870 a

a = 9.03 m/s2

(c) If the scale reads zero, it mean the elevator is falling freely. The acceleration is downwards and its value is 9.8 m/s2.

(d) Tension in cable is 450 N and 670 N.

Answer:

- the coating’s index of refraction is 1.25

- the required thickness is 104.1667 nm

Explanation:

Given the data in the question;

Thickness of coating t = 100 nm

wavelength λ = 500nm

we know that refractive index is;

t = λ/4n

make n, the subject of formula

t4n = λ

n = λ / 4t

we substitute

n = 500 / ( 4 × 100 )

n = 500 / 400

n = 1.25

Therefore, the coating’s index of refraction is 1.25

2)

given that;

Index of refraction of the coating; n = 1.20

λ = 500 nm

thickness of coating t = ?

t = λ / 4n

we substitute

t = 500 / ( 4 × 1.2 )

t = 500 / 4.8

t = 104.1667 nm

Therefore, the required thickness is 104.1667 nm

Answer:

Distance, S = 19.6 meters

Explanation:

Given the following data;

Time = 2 seconds

We know that acceleration due to gravity is equal to 9.8 m/s².

Also, the initial velocity of the object is equal to zero because it's starting from rest.

To find the total distance covered by the object, we would use the second equation of motion;

[tex] S = ut + \frac {1}{2}at^{2}[/tex]

Where;

Substituting into the equation, we have;

[tex] S = 0*2 + \frac {1}{2}*(9.8)*2^{2}[/tex]

[tex] S = 0 + 4.9*4[/tex]

[tex] S = 4.9*4 [/tex]

Distance, S = 19.6 meters

Therefore, the total distance covered by the object is 19.6 meters.

Answer:

In linear motion, the directions of all the vectors describing the system are equal and constant which means the objects move along the same axis and do not change direction. Correct Answer: In a straight line

Explanation:

Answer:

In a straight line. we can also have translational motion which is also a kind of linear motion .

Answer:

Explanation:

Step 1) Combine all resistors into an equivalent overall resistor. These are all in series so you just add them up. Req = 10Ω + 20Ω + 30Ω = 60Ω:

Step 2) Using Ohm's Law, I = V/R = 120/60 = 2 A

Now you know how much current is flowing, and that current flows through each resistor the same. So the current in the 30 Ω resistor is 2.00 amps.

Answer:

Penetration means forward passes can go through the opposition lines. Once these penetrative passes get through each line, it eliminates the line of players it broke through and leaves the player in possession closer to the opposition goal.

Explanation:

Answer:

you can use G.oogle for this question.

Answer:

93.3 degrees Celsius.

Explanation:

Answer:

17.5 m/s

Explanation:

Refer to the attachment!~

Answer:

D) all of the above.

Explanation:

First polarises it, cahrging and discharging occurs at once.

A negatively charged balloon touching a wooden wall then from the given options option D is correct which is all of the above.

Charged matter experiences a force when it is exposed to an electromagnetic field due to the physical property of electric charge. Positive or negative charges can exist in an electric field (commonly carried by protons and electrons, respectively).

Contrary charges attract one another, while like charges repel one another. A neutral object is one that carries no net charge. Classical electrodynamics, the name given to an early understanding of how charged particles interact, is still accurate for issues that do not call for taking into account quantum phenomena.

In the first step it polarizes molecules in the wall, then charging and discharging in the wall will take place at once.

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Answer: it’s A.

Explanation: A pex

Answer:

C. At the highest point of flight.

Explanation:

Given data;

[tex]u_{x} = 4 m/s ,u_{y} = 0, h = 60 m[/tex]

Time of flight,

by third equation of motion ,

[tex]h=\frac{1}{2} gt^{2}[/tex]

[tex]t=\sqrt{\frac{2*60}{9.8} }[/tex]

[tex]t = 3.5 Sec[/tex]

so the range ,

by horizontal component of velocity,([tex]u_{x}[/tex])

R = 4X3.5

R = 14 m

Horizontal component of velocity remain constant in the entire motion.

Answer:

9213 J

Explanation:

Change in Kinetic energy = Change in Potential energy

= 12,928J - 3715J

=9213 J

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Answer:

venus......................

Answer:

Average speed = total distance traveled / total time traveled

V = (2 + 80) / (2 + 40) = 82 / 42 = 2 m / s

Answer:

As the temperature decreases, the peak of the black-body radiation curve moves to lower intensities and longer wavelengths. The black-body radiation graph is also compared with the classical model of Rayleigh and Jeans.

So as you see the wavelengths are in the x axis so all wavelengths are covered.

Black-body radiation provides insight into the thermodynamic equilibrium state of cavity radiation. If each Fourier mode of the equilibrium radiation in an otherwise empty cavity with perfectly reflective walls is considered as a degree of freedom capable of exchanging energy, then, according to the equipartition theorem of classical physics, there would be an equal amount of energy in each mode. Since there are an infinite number of modes this implies infinite heat capacity (infinite energy at any non-zero temperature), as well as an unphysical spectrum of emitted radiation that grows without bound with increasing frequency, a problem known as the ultraviolet catastrophe. Instead, in quantum theory the occupation numbers of the modes are quantized, cutting off the spectrum at high frequency in agreement with experimental observation and resolving the catastrophe. The study of the laws of black bodies and the failure of classical physics to describe them helped establish the foundations of quantum mechanics.

The above explains why the classical assumptions lead to a wrong spectrum.

Explanation:

i don't know if It helps you..parang Ang layo naman Ng sagot ko sa tanong mo

The wave model of light cannot explain the energy emissions from a blackbody radiator, but the particle model of light can be because the electromagnetic wave theory does not explain the black body radiation and the particle model of light can explain it.

Black body radiation is defined as the surface which absorbs all the energy and radiant light falling on it because it absorbs all light of color.

An example of black body radiation is a cavity with a small hole in it.

The Electromagnetic Wave is also called EM Waves which is defined as the waves that are created as a vibration between a magnetic field and electric field.

Light is defined as the electromagnetic radiation which propogates as waves and allows us to make the object visible.

Learn more about the Black Body here: https://brainly.com/question/28887620

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Answer:

Explanation:

The acceleration of an object given it's mass and the force acting on it can be found by using the formula

[tex]a = \frac{f}{m} \\ [/tex]

From the question we have

[tex]a = \frac{6}{2} \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

Force = 1.632 Newton

Explanation:

Given the following data;

Pressure = 102 kPa

Area = 0.016 m²

To find what force the atmosphere exert on the palm of your hand;

Mathematically, pressure is given by the formula;

[tex] Pressure = \frac {Force}{area} [/tex]

Force = 102 * 0.016

Force = 1.632 Newton

Answer:

Spell what?

Can u please mention that too?

Answer:

what

Explanation: how do you spell what please include this in your next post

Answer:

The length of the object in kilometer (km) is 70 x 10⁻⁹ km

The width of the object in kilometers (km) is 47.66 x 10⁻⁹ km

Explanation:

Given;

length of the object = 70 micrometer = 70 μm

the width of the object = 47.66 micrometer =   47.66  μm

The length of the object in meter:

70 micrometer = 70 μm = 70 x 10⁻⁶ m

The length of the object in kilometer (km):

70 x 10⁻⁶ m = 70 x 10⁻⁹ km

The width of the object in meters:

47.66 micrometer = 47.66 μm = 47.66 x 10⁻⁶ m

The width of the object in kilometers (km):

47.66 x 10⁻⁶ m = 47.66 x 10⁻⁹ km

Answer:

1)[tex]t=2.26\: s[/tex]

2)[tex]S=33.9\: m[/tex]

3)[tex]v=26.77\: m/s[/tex]

4)[tex]\alpha=55.92[/tex]

Explanation:

1)

We can use the following equation:

[tex]y_{f}=y_{0}+v_{iy}t-0.5*g*t^{2}[/tex]

Here, the initial velocity in the y-direction is zero, the final y position is zero and the initial y position is 25 m.

[tex]0=25-0.5*9.81*t^{2}[/tex]

[tex]t=2.26\: s[/tex]

2)

The equation of the motion in the x-direction is:

[tex]v_{ix}=\frac{S}{t}[/tex]

[tex]15=\frac{S}{2.26}[/tex]

[tex]S=33.9\: m[/tex]

3)

The velocity in the y-direction of the stone will be:

[tex]v_{fy}=v_{iy}-gt[/tex]

[tex]v_{fy}=0-(9.81*2.26)[/tex]

[tex]v_{fy}=-22.17\: m/s[/tex]

Now, the velocity in the x-direction is 15 m/s then the velocity will be:

[tex]v=\sqrt{v_{x}^{2}+v_{fy}^{2}}=\sqrt{15^{2}+(-22.17)^{2}}[/tex]

[tex]v=26.77\: m/s[/tex]

4)

The angle of this velocity is:

[tex]tan(\alpha)=\frac{22.17}{15}[/tex]

[tex]\alpha=tan^{-1}(\frac{22.17}{15})[/tex]

[tex]\alpha=55.92[/tex]

Then α=55.92° negative from the x-direction.

I hope it helps you!

Answer:

v = 0.064 m/s

Explanation:

Given that,

The mass of two skaters = 75 kg

The mass of a ball = 0.4 kg

The speed of the ball = 6 m/s

The speed of skater = 6 m/s

We need to find the velocity of each of the two skaters.

Under the values given the moment with respect to the ball and which is subsequently transmitted to people it would be given by:

[tex]P=0.4(6)+0.4(6)\\\\=4.8\ kg-m/s[/tex]

We know that,

P = mv

Where

v is the velocity of each skater.

[tex]v=\dfrac{p}{m}\\\\v=\dfrac{4.8}{75}\\\\=0.064\ m/s[/tex]

So, the velocity of each of the skaters is 0.064 m/s.

Answer:

1. Carpenter

2. True

Explanation:

While a mason was working concrete into the formwork, the formwork collapses. The best person to rectify this problem is CARPENTER.

This is because it is the job of the Carpenter to design and build formwork, most especially wooden formwork. Formwork is like casing built to receive concrete and reinforcement during construction. Hence, when formwork collapses either due to stress, tension, or improper construction, it is the job of Carpenter to reconstruct the formwork or rectify the problem.

It is TRUE that when a device made in a workplace had defects. To address this issue the workshop manager should communicate directly with the workshop​. However, this communication will be an instruction on what to do next, and it usually directs those responsible to take action where necessary. For example, a workshop manager communicates to a carpenter about the need to rectify a chair or table that has a defect.

Answer: B

Explanation: because B

Answer:

[tex]\triangle d=21.726m[/tex]

Explanation:

From the question we are told that:

Unimpaired time to hit break [tex]t_i=0.320s[/tex]

Drunk time [tex]t=1s[/tex]

Initial Velocity [tex]v=110km/h[/tex]

Generally the equation for Average velocity is mathematically given by

[tex]V_{avg}=\frac{\triangle d}{\triangle t}[/tex]

Therefore

[tex]\triangle d=v.dt[/tex]

[tex]\triangle d=31.95*(1-0.32)[/tex]

[tex]\triangle d=21.726m[/tex]

Answer:

1. Friction enables us to walk freely.

2. It helps to support ladder against wall.

3. It becomes possible to transfer one form of energy to another.

4. Objects can be piled up without slipping.