A substance a

In a 5.00 km race, one runner runs at a steady 11.4 km/h and another runs at 14.7 km/h . How long does the faster runner have to

topjm [15]

Answer:

0.0986 h or 5 minutes 55 seconds.

Explanation:

Speed: This can be defined as the rate of change of distance of a body. The S.I unit of speed is m/s. Speed is a scalar quantity, because it can only be represented by magnitude alone.

Mathematically,

Speed = distance/time.

S = d/t ........................... Equation 1

making t the subject of the equation

t = d/S ......................... Equation 2

Form the question,

Time taken for the faster runner to reach the finish line

t₁ = d/S₁................... Equation 3

Where t₁ = time taken for the faster runner to reach the finish line, d = distance, S₁ = speed of the faster runner.

Given: d = 5.0 km, S₁ = 14.7 km/h.

Substituting into equation 3

t₁ = 5/14.7

t₁ = 0.340 h

Also,

t₂ = d/S₂................... Equation 4

Where t₂ = time taken for the slower runner to reached the finished line, d = distance, S₂ = speed of the slower runner.

Given: d = 5 km, S₂ = 11.4 km/h.

Substitute into equation 4,

t₂ = 5/11.4

t₂ = 0.4386 h.

The time the faster runner have to wait at the finish line to see the slower runner cross = t₂ - t₁ = 0.4386-0.340

The time the faster runner have to wait at the finish line to see the slower runner cross = 0.0986 h = 5 mins 55 s.

8 0

4 years ago

What is hydrometer? Describe its use and any one type of hydrometer.

nexus9112 [7]

Answer:

An instrument for measuring the density of liquids.

Explanation:

A hydrometer is an instrument used to determine specific gravity. It operates based on the Archimedes principle that a solid body displaces its own weight within a liquid in which it floats. Hydrometers can be divided into two general classes: liquids heavier than water and liquids lighter than water.

Thermohydrometers is one type of hydrometer.

7 0

3 years ago

What is the frequency of a pressure wave of wavelength 2.5 m that is traveling at 1400 m/s?

-BARSIC- [3]

The relationship between the speed, the frequency and the wavelength of a wave is given by:
$f= \frac{v}{\lambda}$
where
f is the frequency
v is the speed of the wave
$\lambda$ is its wavelength

for the pressure wave in this problem, $\lambda=2.5 m$ and v=1400 m/s, therefore its frequency is
$f= \frac{v}{\lambda}= \frac{1400 m/s}{2.5 m}=560 Hz$

5 0

3 years ago

-Para lograr que una pieza de 0,300 kg de cierto metal aumente su temperatura desde 40°C a 60 °C ha sido necesario suministrarle

marishachu [46]

Answer:

parte a) el calor específico es c = 0.383 J /(gr*K)

parte b) la temperatura inicial es T inicial= 52.72 °C

Explanation:

para el primer punto la formula para el calor Q es:

Q = m * c * ( T final - T inicial )

donde

m= masa de la pieza = 0.300 kg = 300 gr

Q = flujo de energía en forma de calor= 2299 J

c = calor específico

T final = temperatura final =40°C

T inicial = temperatura inicial = 60 °C

entonces

Q = m * c * ( T final - T inicial )

c = Q / [ m* ( T final - T inicial ) = 2299 J/[ 300 gr * ( 60 °C - 40°C )]

= 0.383 J /(gr*K)

c = 0.383 J /(gr*K)

para el segundo punto usamos la misma formula

Q = m * c * ( T final - T inicial )

pero

m= 200 gr= 0.200 kg

c=459.8 J/(kg*K) , Q =20.900 J , T final = 280 °C

Q = m * c * ( T final - T inicial )

T inicial = T final - Q/(m*c) =280 °C - 20.900 J/(459.8 J/(kg*K)* 0.200 kg) = 52.72 °C

7 0

3 years ago

2. What mechanism would you use to safely capture emissions?

devlian [24]

Carbon capture is the safest way to capture emission.

<u>Explanation:</u>

Emission of green house gases is one of the most lurking threat above humans. So one of the best ways to reduce emission is to capture the gases like carbon di-oxide or carbon monoxide, nitrous oxide etc. So mostly, the carbon di-oxide gas which is produced as waste is captured using adsorption, absorption, chemical looping etc.

In this method, they are captured from high source points like cement factory etc and then stored in a secluded region. Thus, the adsorption of these gases and then storing them in secluded region is the best option for capturing emission.

5 0

3 years ago