Give me one example of a sport that requires someone to have good reaction time?

A world-class sprinter running a 100 m dash was clocked at 5.4 m/s 1.0 s after starting running and at 9.8 m/s 1.5 s later. In w

cupoosta [38]

Answer:

The output power is greater in the interval from 1.0 s to 2.5 s

Explanation:

Physical Power

It measures the amount of work W an object does in certain time t. The formula needed to compute power is

$\displaystyle P=\frac{W}{t}$

Work can be computed in several ways since we are given the motion conditions, we'll use this formula, for F= applied force, x=distance parallel to F

$W=F.x$

The second Newton's law gives us the net force as

$F=m.a$

being m the mass of the object and a the acceleration it has for a given period of time. In our problem, we have two different behaviors for each interval and we must calculate this force since the acceleration is changing. Let's calculate the acceleration in the first interval. We can use the formula for the final speed vf knowing the initial speed vo (which is 0 because the sprinter starts from rest), the acceleration a, and the time t:

$v_f=v_o+at$

$v_f=at$

Solving for a

$\displaystyle a=\frac{v_f}{t}={5.4}{1}$

$a=5.4\ m/s^2$

The distance traveled in the interval is given by

$\displaystyle x=v_o.t+\frac{a.t^2}{2}$

Since vo=0

$\displaystyle x=\frac{a.t^2}{2}=\frac{5.4(1)^2}{2}$

$x=2.7\ m$

The force is given by

$F=m.a$

We don't know the value of m, so the force is

$F=2.7m$

Computing the work done by the sprinter

$W=F.x=2.7m(5.4)$

$W=14.58m$

The power is finally computed

$\displaystyle P=\frac{W}{t}=\frac{14.58m}{1}$

$P=14.58m$

During the second interval, from t=1 sec to 1.5 sec, the speed changes from 5.4 m/s to 9.8 m/s. This allows us to compute the second acceleration

$\displaystyle a=\frac{v_f-v_o}{t}=\frac{9.8-5.4}{0.5}$

$a=8.8\ m/s^2$

The distance is

$\displaystyle x=(5.4).(0.5)+\frac{8.8(0.5)^2}{2}$

$x=3.8\ m$

The net force is

$F=m(8.8)=8.8m$

The work done by the sprinter is now computed as

$W=8.8m(3.8)=33.44m$

At last, the output power is

$\displaystyle P=\frac{33.44m}{0.5}=66.88m$

By comparing both results, and being m the same for both parts, we conclude the output power is greater in the interval from 1.0 s to 2.5 s

6 0

4 years ago

Power plants can be powered by fossil fuels, such as coal or natural gas, or nuclear power to produce steam to turn turbines to

Naddika [18.5K]

Nuclear energy is cleaner while generating electricity. Nuclear fission provides energy without releasing greenhouse gases such as carbon dioxide. However, nuclear power plants generate significant amounts of radioactive waste. That is why we should not choose nuclear energy over fossil fuel power plants.

7 0

3 years ago

Lera25 [3.4K]

Answer:

C

Explanation:

because it is and it doesn't have to be in the indirect dialog

4 0

3 years ago

Every star is part of a constellation and is assigned a Greek letter within the constellation. Many stars still bear ancient Ara

Andru [333]

Answer:

All 88 constellations are based on figures that originated in Greek and Middle Eastern mythology. (Correct)

The α star in a constellation is usually brighter than the β star. (Correct)

All stars are part of some constellation. (Correct)

The modern constellations have English names rather than Latin like the ancient ones. (Correct)

Explanation:

Constellations were grouped by different civilizations as mean to be oriented when they were making observations of the sky (they could see as maps of certain regions). Each constellation is an arrangement of several stars in a specific figure (animals, mythological characters and objects), things that were important for that civilization.

The letter $\alpha$ is given to the brightest star in a constellation while the other letters of the Greek alphabet are assigned to the other stars that belong to that specific constellation according to their brightness. For example in the Orion constellation the brightest star is Betelgeuse so it is classified with an $\alpha$ ; $\beta$ to Rigel, the second in brightness and so on. That classification system was established by the astronomer Johann Bayer in 1603.

The modern constellations have English names, for example the constellations of Telescopium, Fornax, Sculptor, Chamaeleon, among others.

As constellations represent maps of different regions in the sky, any star will be related with them. For that reason is correct to say that all stars are part of some constellation.

8 0

4 years ago

Evidence gathered from publicly observable behavior is known as _________ evidence.

Dmitriy789 [7]

Empirical because it is what you need to know the source of knowledge gather by observation or experimentation.

6 0

3 years ago