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2 years ago

9

Daniel and Christopher were on a plane traveling at a velocity of 200 km/hr south for 1,000 km. How long (in hours) was the plan

e flying at that velocity?

1 answer:

docker41 [41]2 years ago

3 0

Answer:
5 hours

step-by-step explanation:
very simple just divide 1,000 and 200 to get 5

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Which physical property of iron is being tested in the picture

Molodets [167]

Answer:

Electrical Conductivity

Explanation:

it was on test

7 0

2 years ago

A force of 70 N is applied to a 28 kg rock causing it to slow down from 25 m/s to 15 m/s, a change in velocity of 10 m/s. How lo

maksim [4K]

Answer: 4 s

Explanation:

Given

The applied force is 70 N

mass of the rock is 28 kg

initial velocity $u=25\ m/s$

final velocity $v=15\ m/s$

Deceleration provided by force is

$a=-\dfrac{70}{28}=-2.5\ m/s^2$

using the equation of motion

$v=u+at\\\Rightarrow 15=25-2.5t\\\Rightarrow 2.5t=10\\\Rightarrow t=4\ s$

7 0

2 years ago

Two charged bees land simultaneously on flowers that are separated by a finite distance. For a few moments, the charged bees res

damaskus [11]

Answer:

Same, the electric fields point in opposite directions and therefore cancel at some midpoint.

Explanation:

The Electric field net at some point between them is zero, only if they point in opposite direction (they cancel to the each other). In order the electric fields have opposite direction, at some point between the bees , the bees must have the same sign of electric charge

3 0

2 years ago

The body went 450 meters within 30 seconds of starting the movement. In what time did the first 50 meters go?

Andrew [12]

3.33 seconds.

<u>Explanation:</u>

We can find the speed of the body using the formula,

Speed = Distance traveled in meters / time taken in seconds

= 450 m / 30 seconds

= 15 m/s

So per second the distance traveled by the body is 15 m.

So time needed to travel 50 m can be found as,

time = distance/speed

= 50 m / 15 m /s

= 3.33 s

8 0

2 years ago

Water is being boiled in an open kettle that has a 0.52-cm-thick circular aluminum bottom with a radius of 12.0 cm. If the water

tangare [24]

Answer:

$T_b=107.3784\ ^{\circ}C$

Explanation:

Given:

thickness of the base of the kettle, $dx=0.52\ cm=5.2\times 10^{-3}\ m$

radius of the base of the kettle, $r=0.12\ m$

temperature of the top surface of the kettle base, $T_t=100^{\circ}C$

rate of heat transfer through the kettle to boil water, $\dot Q=0.409\ kg.min^{-1}$

We have the latent heat vaporization of water, $L=2260\times 10^3\ J.kg^{-1}$

and thermal conductivity of aluminium, $k=240\ W.m^{-1}.K^{-1}$

<u>So, the heat rate:</u>

$\dot Q=\frac{0.409\times 2260000}{60}$

$\dot Q=15405.67\ W$

<u>From the Fourier's law of conduction we have:</u>

$\dot Q=k.A.\frac{dT}{dx}$

$\dot Q=k\times \pi.r^2\times \frac{T_b-T_t}{5.2\times 10^{-3}}$

where:

$A=$ area of the surface through which conduction occurs

$T_b=$ temperature of the bottom surface

$15405.67=240\times \pi\times 0.12^2\times \frac{T_b-100}{5.2\times 10^{-3}}$

$T_b=107.3784\ ^{\circ}C$ is the temperature of the bottom of the base surface of the kettle.

6 0

2 years ago