All categories

3 years ago

How do you know that waves sent from the sun to earth are not mechanical waves? Explain

1 answer:

3 0

Mechanical waves require matter to travel medium. If there is no substance or matter to travel through, mechanical waves cannot propagate.

Since space is mostly vacuum, there is no medium for waves to travel through: waves sent by the sun (electromagnetic waves) are not mechanical waves

You might be interested in

1.<br>Force that pulls toward the center of mass.<br><br>

kondaur [170]

Gravity if I’m not mistaken

7 0

3 years ago

Read 2 more answers

Tudy the images about geologic time.

Inessa [10]

Answer:

The first flowering plants appeared in the Mesozoic era, not the Paleozoic era.

Explanation:

The Mesozoic era was an era where numerous organisms started to develop in very unique and more advanced ways, both the animals and the plants. In the last period of the Mesozoic, the Cretaceous, the first flowering plants started to appear on the scene. This was revolutionary trait of the plants, and soon these plants started to occupy more and more space and became one of the dominant organisms on the planet. Other important evolution that took place in this period are the appearance of the dinosaurs and the mammals, both becoming the dominant animals on the planet, first the dinosaurs, after that the mammals.

8 0

3 years ago

Read 2 more answers

What is the speed of sound

Charra [1.4K]

Answer:it is 343 meter per second in air.

Explanation:

it is 5 times more in liquids than in gases and 15 times more in solids than in gases.In air it is affected by various physical conditions such as pressure,humidity and temperature.

7 0

3 years ago

Read 2 more answers

The record time for a Tour de France cyclist to ascend the 1100-m-high Alpe d'Huez is 37.5 min. The rider and his bike had a mas

Leni [432]

Answer

given,

height of Alpe d'Huez = 1100-m

time = 37.5 min

mass of the rider and his bike = 65 Kg

the metabolic power to ride = 700 W

U = m g y

U = 65 x 9.8 x 1100

U = 700700 J

since efficiency is 25%

$E_{chem} = \dfrac{U}{e}$

$E_{chem} = \dfrac{700700}{0.25}$

$E_{chem} = 2802800$

$E_{chem} = \dfrac{2802800}{4.19 \time 10^3}$

$E_{chem} =668.9\ cal$

b) $P = \dfrac{E_{chem}}{t}$

$P = \dfrac{2802800}{37.5\times 60\ s}$

P = 1245.68 W

8 0

3 years ago

Read 2 more answers

if a Firebird travels at a velocity of 0 to 60 mph in four seconds traveling east what was the acceleration of the Firebird

Tresset [83]

Answer:

6.7 m/s^2

Explanation:

The formula of acceleration is:

$\displaystyle{\vec{a} = \dfrac{\Delta \vec{v}}{\Delta t} = \dfrac{v_2 - v_1}{t_2-t_1}}$

where $\displaystyle{\vec{a}}$ is acceleration, $\displaystyle{\vec{v}}$ is velocity and $\displaystyle{t}$ is time. $\displaystyle{v_2}$ means final velocity. $\displaystyle{v_1}$ means initial velocity, $\displaystyle{t_2}$ means final time and $\displaystyle{t_1}$ means initial time.

We are given that the Firebird travels at velocity of 0 to 60 mph in four seconds. Therefore:

Our initial velocity starts at 0 mph.
Our final velocity is at 60 mph.
Our initial time is 0 second.
Our final time is 4 seconds.

Since it travels to the east then our vector will be positive. However, acceleration has to be in m/s^2 unit (Sl unit) so we'll have to convert from mph (miles per hours) to m/s (meters per second) first.

We know that:

A mile equals to 1609.344 meters.
An hour equals to 60 minutes which a minute equals to 60 seconds. So 60 minutes will equal to 3600 seconds.

Now we divide 1609.344 by 3600 to find a unit rate of m/s:

$\displaystyle{\dfrac{1609.344}{3600} \ \, \sf{m/s}}\\\\\displaystyle{= 0.44704 \ \, \sf{m/s}}$

Now multiply 0.44704 m/s by 0 and 60 to get velocity in m/s unit:

Initial velocity = 0 m/s
Final velocity = 60 * 0.44704 = 26.82 m/s

Time is already in second so no need for conversion. Substitute known information in the formula:

$\displaystyle{\vec{a} = \dfrac{26.82-0}{4-0}}\\\\\displaystyle{\vec{a} = \dfrac{26.82}{4}}\\\\\displaystyle{\vec{a} = 6.7 \ \, \sf{m/s^2}}$

Therefore, the Firebird will accelerate at the rate of 6.7 m/s^2.

3 0

2 years ago