A jet play sits on the runway and then rapidly accelerates does it go to potential to kinetic energy?

Radiant heat makes it impossible to stand close to a hot lava flow. Calculate the rate of heat loss by radiation from 1.00 m^2 o

VARVARA [1.3K]

The rate of heat loss by radiation is equal to -207.5kW

Why?

To calculate the heat loss rate (or heat transfer rate) by radiation, from the given situation, we can use the following formula:

$HeatLossRate=E*S*A*((T_{cold})^{4} -(T_{hot})^{4} )$

Where,

E, is the emissivity of the body.

A, is the area of the body.

T, are the temperatures.

S, is the Stefan-Boltzmann constant, which is equal to:

$5.67x10^{-8}\frac{W}{m^{2}*K^{-4} }$

Now, before substitute the given information, we must remember that the given formula works with absolute temperatures (Kelvin), so, we need to convert the given values of temperature from Celsius degrees to Kelvin.

We know that:

$K=Celsius+273.15$

So, converting we have:

$T_{1}=1110\°C+273.15=1383.15K\\\\T_{2}=36.2\°C+273.15=309.35K$

Therefore, substituting the given information and calculating, we have:

$HeatLossRate=E*S*A*((T_{cold})^{4} -(T_{hot})^{4} )$

$HeatLossRate=1*5.67x10^{-8}\frac{W}{m^{2}*K^{-4} }*1m^{2} *((309.35K)^{4} -(1383.15})^{4} )\\\\HeatLossRate=5.67x10^{-8}\frac{W}{K^{-4} }*(95697.42K^{4} -3.66x10^{12}K^{4})\\ \\HeatLossRate=5.67x10^{-8}\frac{W}{K^{-4} }*(-3.66x10^{12} K^{4})=-207522W=-207.5kW$

Hence, we have that the rate of heat loss is equal to -207.5kW.

8 0

3 years ago

A woman climbs up a ladder in 1.37 s at 2.20 m/s. How tall is the ladder?

ArbitrLikvidat [17]

Answer:

The ladder is 3.014 m tall.

Explanation:

To solve this problem, we must use the following formula:

v = x/t

where v represents the woman’s velocity, x represents the distance she climbed (the height of the ladder), and t represents the time it took her to move this distance

If we plug in the values we are given for the problem, we get:

v = x/t

2.20 = x/1.37

To solve this equation for x (the height of the ladder), we must multiply both sides by 1.37. If we do this, we get:

x = (2.20 * 1.37)

x = 3.014 m

Therefore, the ladder is 3.014 m tall.

Hope this helps!

6 0

4 years ago

Read 2 more answers

A speeding Thunderbird left skid marks on the road that were 76.7 m long when it came to a stop. If the acceleration of the car

FrozenT [24]

Answer: 39.2 m/s

Explanation:

You can use the kinematic equation:

$v_f^2=v_i^2+2a*d$

We know the final velocity because it says it came to a stop. So now all we gotta do is plug in.

$0^2=v_i^2+2(-10)(76.7)\\v_i^2=1,534\\v_i=\sqrt{1534} \\=39.166 m/s$

4 0

3 years ago

If the fundamental frequency of a musical instrument is 42Hz, what is the frequency of the second harmonic?

timurjin [86]

For the majority of instruments f = n f0 where f is the resonating frequency, n is any whole number and f0 is the fundamental.
This applies to trumpets, violins, flutes and a broad range. 
In such a case the first harmonic would be at n=1 and the second harmonic would be at n=2 

which gives a frequency of 84 Hz

7 0

3 years ago

Define these terms about speed and state their units speed distance covered time taken

Neporo4naja [7]

Explanation:

Speed is the rate of change of distance with time. It is a scalar quantity with magnitude both no direction.

Speed = $\frac{distance}{time}$

The unit is m/s or km/hr or mile/hr

Distance covered is simply the length of the path traveled.

The unit is m or km or miles

Time taken is the duration of an event.

The unit is seconds or minutes or hour.

4 0

3 years ago