Which angle is the angle of reflection? (5 points) 01 O 2 O 3

The current theory of the structure of the Earth, called plate tectonics, tells us that the continents are in constant motion.

lesya [120]

Answer:

(a) m = 1.6 x 10²¹ kg

(b) K.E = 2.536 x 10¹¹ J

(c) v = 7.12 x 10⁵ m/s

Explanation:

(a)

First we find the volume of the continent:

V = L*W*H

where,

V = Volume of Slab = ?

L = Length of Slab = 4450 km = 4.45 x 10⁶ m

W = Width of Slab = 4450 km = 4.45 x 10⁶ m

H = Height of Slab = 31 km = 3.1 x 10⁴ m

Therefore,

V = (4.45 x 10⁶ m)(4.45 x 10⁶ m)(3.1 x 10⁴ m)

V = 6.138 x 10¹⁷ m³

Now, we find the mass:

m = density*V

m = (2620 kg/m³)(6.138 x 10¹⁷ m³)

m = 1.6 x 10²¹ kg

(b)

The kinetic energy will be:

K.E = (1/2)mv²

where,

v = speed = (1 cm/year)(0.01 m/1 cm)(1 year/365 days)(1 day/24 h)(1 h/3600 s)

v = 3.17 x 10⁻¹⁰ m/s

Therefore,

K.E = (1/2)(1.6 x 10²¹ kg)(3.17 x 10⁻¹⁰ m/s)²

K.E = 2.536 x 10¹¹ J

(c)

For the same kinetic energy but mass = 77 kg:

K.E = (1/2)mv²

2.536 x 10¹¹ J = (1/2)(77 kg)v²

v = √(2)(2.536 x 10¹¹ J)

v = 7.12 x 10⁵ m/s

7 0

3 years ago

Margy is trying to improve her cardio endurance by performing an exercise in which she alternates walking and running 100.0 m ea

Kipish [7]

Answer:

6.5 m/s

Explanation:

We are given that

Distance, s=100 m

Initial speed, u=1.4 m/s

Acceleration, $a=0.20 m/s^2$

We have to find the final velocity at the end of the 100.0 m.

We know that

$v^2-u^2=2as$

Using the formula

$v^2-(1.4)^2=2\times 0.20\times 100$

$v^2-1.96=40$

$v^2=40+1.96$

$v^2=41.96$

$v=\sqrt{41.96}$

$v=6.5 m/s$

Hence, her final velocity at the end of the 100.0 m=6.5 m/s

5 0

3 years ago

What is the speed of a wave if it has a wavelength of 42 m and a frequency of 7 hertz?

Nimfa-mama [501]

Answer:

♕ $\large{ \red{ \tt{Step - By - Step \: Explanation}}}$

☃ $\underline{ \underline{ \blue{ \large{ \tt{G \: I \: V \: E\: N}}}}} :$

Frequency ( f ) = 7 Hertz
Wavelength ( λ ) = 42m

♨ $\underline {\underline{ \orange{ \large{ \tt{T \: O \: \: F \: I \: N\: D}}}} }:$

Wave velocity ( v )

☄ $\underline{ \underline{ \large{ \pink{ \tt{S\: O \: L \: U \: T\: I \: O \: N}}}}}:$

✧ $\red{ \boxed{ \large{ \purple{ \sf{Wave \: velocity(v) = Frequency(f) \times Wavelength(λ)}}}}}$

~Plug the known values and then multiply!

↦ $\large{ \tt{7 \times 42}}$

↦ $\boxed{ \boxed{ \large{ \bold{ \tt{294 \: m {s}^ {- 1} }}}}}$

☥ $\large{ \boxed{ \boxed{ \large{ \tt{Our \: Final \: Answer : \underline{ \large{ \tt{294 \: m {s}^{ - 1}}}}}}}}}$

---------------------------------------------------------------

❁ $\underline{ \large{ \red{ \tt{D\: E\: T \: A \: I \: L\: E \: D \: \: I\: N \: F \: O}}}} :$

Frequency ( f ) : The number of complete waves , set up in a medium in one second is called frequency of the wave. The SI unit of frequency is Hertz ( Hz ). For example : if a sound wave completes 15 compressions and 15 rarefactions in one second , it's frequency is 15 Hz.

Wavelength ( λ ) : The distance between two consecutive troughs or crests in a transverse wave or the distance between two consecutive compressions or rarefactions in a longitudinal wave us called wavelength. It is the distance travelled by a wave in a time equal to it's time period. It's SI unit is metre ( m ).

Wave velocity ( v ) : The velocity with which a wave propagates in a medium is called wave velocity. It's SI unit is m/s.

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MARRY : Goals

♪ Hope I helped! ♡

☂ Have a wonderful day / night ! ツ

✎ $\underbrace{ \overbrace{ \mathfrak{Carry \: On \: Learning}}}$ ✔

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4 0

3 years ago

I need the correct answer for this question please

kirill115 [55]

Try C. a downward gravitational force exerted by Earth

7 0

3 years ago

If 2 electrically charged objects repel one another , which of the statements could be true, one object has more electrons, the

fiasKO [112]

Both objects have the same electrical charge. Opposite charges attract. And if they were neutral they would not do anything.

6 0

3 years ago

Read 2 more answers