Radiation transfers energy by moving matter. Please select the best answer from the choices provided T F

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:

<em>The output power is greater in the interval from 1.0 s to 2.5 s</em>

Explanation:

<u>Physical Power </u>

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

Are the stack temperature and oxygen reasonable for these operating conditions? if not, what oxygen and stack temperature would

Anton [14]

Stack temperatures typically range from 350 to 450 degrees Fahrenheit. A 2.5% efficiency loss occurs for every 100 degrees over that temperature. The majority of buildings schedule annual boiler cleanings at regular intervals, but if you see those figures rise, it's time for a cleaning.

Excess air is required to completely burn the fuel since the air and fuel cannot combine exactly in a burner. Additionally, any leaks in the heater will draw air into the firebox that doesn't pass through the burners since the furnace or boiler firebox operates at a little negative gauge pressure. Fuels that are gaseous, like natural gas, burn more readily than fuels that are liquid or solid. Depending on the fuel type, different surplus air requirements will apply.

Learn more about temperature here-

brainly.com/question/15267055

#SPJ4

3 0

1 year ago

Who was the most famous member of the Underground Railroad?

MArishka [77]

Answer:

Harriet Tubman

Explanation:

7 0

3 years ago

Read 2 more answers

For each of the following velocity vectors, give the vector component, the scalar component, and the magnitude. (a) v = 48.0j m/

Oduvanchick [21]

Obtaining the component part of the letter 'i' warns that it is the velocity is oriented on the X axis. At the same time the numeric part, in this particular case will represent the scalar part and therefore the magnitude of the vector.

The velocity is

$\vec{v} = 48.0\hat{i} \text{ m/s }$

The vector component of the velocity is

$v_x = 48.0m/s$

The scalar component of the velocity is

$v = 48.0m/s$

The magnitude of the velocity is

$v = 48.0m/s$

3 0

4 years ago

Olivia wants to find out whether a substance will fluoresce. She says she should put it in a microwave oven. Do you agree with h

kompoz [17]

Answer:

In disagreement

Explanation:

Fluorescence can be defined as the phenomenon by which an object emits visible light when placed in front of ultraviolet light. In fluorescence, the absorbed light increases the energy band of the electrons, causing them to go into a more excited state. The electrons, before they release the absorbed energy in the form of light, lose a part of the energy due to the vibration of the molecules. When they return to their initial state, the electrons will emit light.

While microwaves are electromagnetic waves whose frequency is high, and are used for the transmission of high-speed telegraphic signals and for the communication of satellites and do not emit light.

4 0

3 years ago

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