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3 years ago

Why does the evaporation of sweat cool down your skin?

2 answers:

6 0

So sweat helps cool you down two ways. First, it makes your skin feel cooler when it's wet. And when it evaporates it removes some heat. But sweat will only evaporatoin an environment where there isn't much water in the air.

Sergeu [11.5K]3 years ago

4 0

It removes the heat on your skin

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When you observe the world and see something that you don't understand, you make a hypothesis that you try to prove. This either

Whitepunk [10]

Just like the water cycle, rocks undergo changes of form in a rock cycle. A metamorphic rock can become an igneous rock, or a sedimentary rock can become a metamorphic one. Unlike the water cycle, you can’t see the process happening on a day-to-day basis. Rocks change very slowly under normal conditions, but sometimes catastrophic events like a volcanic eruption or a flood can speed up the process. So what are the three types of rocks, and how do they change into each other? Keep reading to find out!

5 0

4 years ago

A water wave travels 36 meters in 15 seconds. What is the speed of the wave?

atroni [7]

2.4 meters per second

I hope this helps

5 0

3 years ago

Read 2 more answers

Object A is moving due east, while object B is moving due north. They collide and stick together in a completely inelastic colli

Pie

Answer:

a) v = 3,843 m / s, b) 46.7º North- East

Explanation:

Moment is a vector quantity, so one of the best ways to solve this problem is to solve each component separately.

The system is formed by the two vehicles so that the moment is preserved during the crash

Direction to the East

initial instant. Before the crash

p₀ = mₐ vₐ₀

final insttne. After the crash

p_f = (mₐ + m_b) vₓ

p₀ = p_f

mₐ vₐ₀ = (mₐ + m_b) vₓ

vₓ = $\frac{m_a}{m_a + m_b} \ v_{ao}$

let's calculate

vₓ = $\frac{16.7}{16.7 + 29.3} \ 7.26$

vₓ = 2,636 m / s

direction north

initial p₀ = m_b v_{bo}

final p_f = (mₐ + m_b) v_y

p₀ = p_f

m_b v_{bo} = (mₐ + m_b) v_y

v_y = $\frac{m_b}{m_a+m_b} \ v_{bo}$

let's calculate

v_y = $\frac{29.3}{16.7 + 29.3} \ 4.39$

v_y = 2.796 m / s

the final speed of the two two vehicles is

v = (2,636 i ^ + 2,796 j ^) m / s

a) the magnitude of the velocity

let's use the Pythagorean theorem

v = $\sqrt{v_x^2 + v_y^2}$

v = $\sqrt{2.636^2 + 2.796^2}$

v = 3,843 m / s

b) let's use trigonometry to find the direction

tan θ = v_y / vₓ

θ = tan⁻¹ v_y / vₓ

θ = tan⁻¹ (2,796 / 2,636)

θ = 46.7º

This direction is 46.7º North East

7 0

3 years ago

An ultrasound unit is being used to measure a patient's heartbeat by combining the emitted 2.0 MHz signal with the sound waves r

alexandr402 [8]

Hi there,
for this question we have:
Signal 2.0 MHz = Emitted so we can call it $f_e$
and we need the Reflected = $f_{r}$
In this question, we have a source which goes to the heart and a reflected which comes back from the heart and we need the speed of the reflected.
So you should know that the speed of reflected is lower than the source(Emitted).
we also know: ΔBeat frequency(max) = 560 Hz = $f_{b}$
so we have:
$f_{e}$ - $f_{r}$ = $f_{b}$
so frequency of Reflected is:
2.0 × 10^6 Hz - 560 Hz = 1.99 × 10^6 Hz = $f_{r}$
now you know that Lambda = v/f
so if we find the lambda with our Emitted then we can find v with the Reflected:
Lambda = 1540(m/s) / 2.0 × 10^6 Hz = 7.7 × 10^-4 m
=> $v_{max}$ = (lambda)( $f_{r}$
=> 7.7 × 10^-4m (1.99 × 10^6Hz) = 1532 m/s
so the $v_{max}$ is equal to 1532 m/s :)))
This question is solved by two top teachers as fast as they could :))
I hope this is helpful
have a nice day

8 0

4 years ago

A number written in scientific notation has the form a×10k, where 1≤a<10 and k is an integer, that is, k is one of ...−3,−2,−

Evgen [1.6K]

scientific notation is given as

$a \times 10^k$