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3 years ago

The specific gravity of upper mantle rock is: A. 2.7 B. 3.0 C. 3.3 D. 5.5

1 answer:

7 0

C. Upper mantle is further supdivided near the surface of two zones: - Asthenosphere - mean density about 3.3 g/cc. Denser and hotter than lithosphere above.

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If I punch a wall, what is the Newton's 3rd Law Pair force?

UkoKoshka [18]

For every reaction, there is an equal and opposite reaction. This means that with every interaction, theres a pair of opposite forces on the object.

4 0

3 years ago

Suppose 8.50 ✕ 10^5 J of energy are transferred to 1.63 kg of ice at 0°C. The latent heat of fusion and specific heat of water a

PolarNik [594]

Answer:

(a) 5.43 x 10⁵ J

(b) 3.07 x 10⁵ J

Explanation:

(a)

$L_{f}$ = Latent heat of fusion of ice to water = 3.33 x 10⁵ J/kg

m = mass of ice = 1.63 kg

$Q_{f}$ = Energy required to melt the ice

Energy required to melt the ice is given as

$Q_{f}$ = m $L_{f}$

$Q_{f}$ = (1.63) (3.33 x 10⁵)

$Q_{f}$ = 5.43 x 10⁵ J

(b)

E = Total energy transferred = 8.50 x 10⁵ J

Q = Amount of energy remaining to raise the temperature

Using conservation of energy

E = $Q_{f}$ + Q

8.50 x 10⁵ = 5.43 x 10⁵ + Q

Q = 3.07 x 10⁵ J

(c)

T₀ = initial temperature = 0°C

T = Final temperature

m = mass of water = 1.63 kg

c = specific heat of water = 4186 J/(kg °C)

Q = Amount of energy to raise the temperature of water = 3.07 x 10⁵ J

Using the equation

Q = m c (T - T₀)

3.07 x 10⁵ = (1.63) (4186) (T - 0)

T = 45 °C

5 0

3 years ago

Given that:<br><br> = 2i + 9j ; and ⃗ = -i – 4j . Find . ⃗

Marat540 [252]

Answer:

A.B = -38

Explanation:

A = 2i + 9j and B = -i - 4j.

So, A.B = (2i + 9j).(-i - 4j)

= 2i.(-i) + 2i.(-4j) + 9j.(-i) + 9j.(-4j)

= -2i.i - 8i.j - 9j.i - 36j.j

since i.i = 1, j.j = 1, i.j = 0 and j.i = 0, we have

A.B = -2(1) - 8(0) - 9(0) - 36(1)

A.B = -2 - 0 - 0 - 36

A.B = -38

5 0

3 years ago

What is the frequency of a tuning fork that vibrates 518 times in 3.50 s?

Serga [27]

Given:

The number of vibrations of the tuning fork is,

$51\text{8 times}$

in,

$t=3.50\text{ s}$

To find:

The frequency of the fork

Explanation:

The frequency is the number of vibrations in 1 second

The frequency for the given fork is,

$\begin{gathered} \frac{The\text{ total vibrations}}{The\text{ time}} \\ =\frac{518}{3.50} \\ =148\text{ Hz} \end{gathered}$

Hence, the frequency is 148 Hz.

7 0

1 year ago

A 78 kg skydiver can be modeled as a rectangular "box" with dimensions 24 cm × 35 cm × 170 cm . If he falls feet first, his drag

ANTONII [103]

Answer:

The terminal speed of his is 137.68 m/s.

Explanation:

Given that,

Mass of skydiver = 78 kg

Area of box $A =24\times35=840\ cm$

Drag coefficient = 0.80

Density of air $\rho= 1.2\times kg/m^3$

We need to calculate the terminal velocity

Using formula of drag force

$F_{d} = \dfrac{1}{2}\rho v^2Ac$

Where,

$\rho$ = density of air

A = area

C= coefficient of drag

Put the value into the formula

$78\times9.8=\dfrac{1}{2}\times1.2\times v^2\times24\times10^{-2}\times35\times10^{-2}\times0.80$

$v^2=\dfrac{2\times78\times9.8}{1.2\times24\times10^{-2}\times35\times10^{-2}\times0.80}$

$v=\sqrt{\dfrac{2\times78\times9.8}{1.2\times24\times10^{-2}\times35\times10^{-2}\times0.80}}$

$v=137.68\ m/s$

Hence, The terminal speed of his is 137.68 m/s.

3 0

3 years ago