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3 years ago

Convection is a process of heat transfer. In the earth, convection occurs because of heat and pressure from the core.

Physics

2 answers:

Aliun [14]3 years ago

7 0

Answer:

I BELIEVE THE ANSWER A I REMEMBER THAT QUESTION WHEN I DID IT SO THATS THE BEST ONE OUT OF THE 3

Explanation:

Travka [436]3 years ago

3 0

Answer:

Explanation:

convection is like when the bubble forming at the bottom of a pot of water rise and the cool water falls to the bottom and then heat up and rise to the top and so on which is why the pot heats mostly evenly.

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Why do we need gametes?

andrew11 [14]

Answer:

Gametes are the cells used during sexual reproduction to produce a new individual organism.

Explanation:

The male gamete or sperm, is a smaller, mobile cell that meets up with the much larger and less mobile female gamete, egg or ova.

6 0

2 years ago

Read 2 more answers

A particle starts from the origin at t = 0 with an initial velocity of 4.8 m/s along the positive x axis.If the acceleration is

tia_tia [17]

Answer:

Part a)

Velocity = 6.9 m/s

Part b)

Position = (3.6 m, 5.175 m)

Explanation:

Initial position of the particle is ORIGIN

also it initial speed is along +X direction given as

$v_x = 4.8 m/s$

now the acceleration is given as

$\vec a = -3.2 \hat i + 4.6 \hat j$

when particle reaches to its maximum x coordinate then its velocity in x direction will become zero

so we will have

$v_f = v_i + at$

$0 = 4.8 - 3.2 t$

$t = 1.5 s$

Part a)

the velocity of the particle at this moment in Y direction is given as

$v_f_y = v_i + at$

$v_f_y = 0 + 4.6(1.5)$

$v_f_y = 6.9 m/s$

Part b)

X coordinate of the particle at this time

$x = v_x t + \frac{1}{2}a_x t^2$

$x = 4.8(1.5) - \frac{1}{2}(3.2)(1.5^2)$

$x = 3.6 m$

Y coordinate of the particle at this time

$y = v_y t + \frac{1}{2}a_y t^2$

$y = 0(1.5) + \frac{1}{2}(4.6)(1.5^2)$

$y = +5.175 m$

so position is given as (3.6 m, 5.175 m)

5 0

3 years ago

A block oscillating on a spring has period T = 2.8 s . (Note: You do not know values for either m or k. Do not assume any partic

olasank [31]

Answer:

Part a)

T = 3.96 s

Part b)

T = 1.98 s

Part c)

T = 2.8 s

Explanation:

As we know that time period of spring block system is given as

$T = 2\pi\sqrt{\frac{m}{k}}$

T = 2.8 s

Part a)

If the mass of the block attached is doubled

then we will have

$T' = 2\pi\sqrt{\frac{2m}{k}}$

$T' = \sqrt2 T$

$T' = 3.96 s$

Part b)

If the spring constant is doubled

then we have

$T' = 2\pi\sqrt{\frac{m}{2k}}$

$T' = \frac{T}{\sqrt2}$

$T' = 1.98 s$

Part c)

If the amplitude is halved but mass and spring constant will remain the same

so here we know that time period does not depends on Amplitude

so we will have

$T = 2\pi\sqrt{\frac{m}{k}}$

T = 2.8 s

7 0

2 years ago

Kathy tests her new sports car by racing with Stan, an experienced racer. Both start from rest, but Kathy leaves the starting li

erica [24]

Answer:

(a) 10 s

(b) 236.5 m

(c) Kathy's speed = 47.3 m/s

Stan's speed = 42.9 m/s

Explanation:

<u>Given:</u>

$u_k$ = initial speed of Kathy = 0 m/s

$u_s$ = initial speed of Stan = 0 m/s
$a_k$ = acceleration of Kathy = $4.73\ m/s^2$

$a_s$ = acceleration of Stan = $3.9\ m/s^2$

<u>Assumptions:</u>

$v_k$ = final speed of Kathy when see catches Stan
$v_s$ = final speed of Stan when Kathy catches him
$s_k$ = distance traveled by Kathy to catch Stan
$s_s$ = distance traveled by Stan when Kathy catches him
$t_k$ = time taken by Kathy to catch Stan = $t$
$t_s$ = time interval in which Kathy catches Stan = $t+1$

Part (a):

Kathy will catch Stan only if the distances traveled by each of them are equal at the same instant.

$\therefore s_s=s_k\\\Rightarrow u_st_s+\dfrac{1}{2}a_st_s^2=u_kt_k+\dfrac{1}{2}a_kt_k^2\\ \Rightarrow (0)(t+1)+\dfrac{1}{2}(3.9)(t+1)^2=(0)(t)+\dfrac{1}{2}(4.73)t^2\\ \Rightarrow \dfrac{1}{2}(3.9)(t+1)^2=\dfrac{1}{2}(4.73)t^2\\\Rightarrow (3.9)(t+1)^2=(4.73)t^2\\\Rightarrow \dfrac{(t+1)^2}{t^2}=\dfrac{4.73}{3.9}\\\textrm{Taking square root in both sides}\\\dfrac{t+1}{t}= 1.1\\\Rightarrow t+1=1.1t\\\Rightarrow 0.1t = 1\\\Rightarrow t = 10\\$

Hence, Kathy catches Stan after 11 s from the Stan's starting times.

Part (b):

Distance traveled by Kathy to catch Stan will be distance the distance traveled by her in 10 s.

$s_s = u_kt_k+\dfrac{1}{2}a_kt_k^2\\\Rightarrow s_s= (0)(t)+\dfrac{1}{2}(4.73)t^2\\\Rightarrow s_s= \dfrac{1}{2}(4.73)(10)^2\\\Rightarrow s_s= 236.5$

Hence, Kathy traveled a distance of 236.5 m to overtake Stan.

Part (c):

$v_k = u_k+a_kt_k\\\Rightarrow v_k = 0+(4.73)(t)\\\Rightarrow v_k = (4.73)(10)\\\Rightarrow v_k =47.3$

The speed of Kathy at the instant she catches Stan is 47.3 m/s.

$v_s = u_s+a_st_s\\\Rightarrow v_s = 0+(3.9)(t+1)\\\Rightarrow v_s = (3.9)(10+1)\\\Rightarrow v_s =42.9$

The speed of Stan at the instant Kathy catches him is 42.9 m/s.

7 0

3 years ago

While solving a problem, Tran calculates an answer that has coulomb-volts as the units.

Bess [88]

Apparently, the question is looking for A. electric potential energy;

but I don't think that's quite right. Electric potential difference is expressed in Joules / Coulomb which is the work to move a charge between 2 points

Example: If the electric field between, say, between 2 capacitor plates is

E = 100 Newtons / Coulomb then the work done in moving a unit of charge from the negative plate to the positive plate separted by 1 cm is

V = E * d = 100 Newtons / Coulomb * .01 meters = 1 Newton-meter / Coulomb

= 1 Joule / Coulomb which is the electric potential or potential difference

(The definition of electric potential between points is "the work moving a unit positive test charge from one point to the other")

Now in our above example where V = 1 Joule / Coulomb

if we move 10 Coulombs from the negative plate to the positive plate

W = V Q = 1 Joule / Coulomb * 10 Coulombs = 10 Joules

where work done has the correct units of Joules.

Your textbook should help clarify this.

4 0

2 years ago