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3 years ago

9

Car A has a mass of 1,200 kg and is traveling at a rate of 22km/hr. It collides with car B has a mass of 1,900 kg and is traveli

ng in the same direction at 25km/hr. Which of the following statements is true?

1 answer:

Zina [86]3 years ago

7 0

<span>The momentum before the collision is equal to the momentum after the collision</span>

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The work-energy theorem states that the work done on an object is equal to a change in which quantity?

Fynjy0 [20]

The work-energy theorem states that the net work done by the forces on an object equals the change in its kinetic energy.

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2 years ago

Water (density = 1x10^3 kg/m^3) flows at 15.5 m/s through a pipe with radius 0.040 m. The pipe goes up to the second floor of th

RUDIKE [14]

Answer:

The speed of the water flow in the pipe on the second floor is approximately 13.1 meters per second.

Explanation:

By assuming that fluid is incompressible and there are no heat and work interaction through the line of current corresponding to the pipe, we can calculate the speed of the water floor in the pipe on the second floor by Bernoulli's Principle, whose model is:

$P_{1} + \frac{\rho\cdot v_{1}^{2}}{2}+\rho\cdot g\cdot z_{1} = P_{2} + \frac{\rho\cdot v_{2}^{2}}{2}+\rho\cdot g\cdot z_{2}$ (1)

Where:

$P_{1}$ , $P_{2}$ - Pressures of the water on the first and second floors, measured in pascals.

$\rho$ - Density of water, measured in kilograms per cubic meter.

$v_{1}$ , $v_{2}$ - Speed of the water on the first and second floors, measured in meters per second.

$z_{1}$ , $z_{2}$ - Heights of the water on the first and second floors, measured in meters.

Now we clear the final speed of the water flow:

$\frac{\rho\cdot v_{2}^{2}}{2} = P_{1}-P_{2}+\rho \cdot \left[\frac{v_{1}^{2}}{2}+g\cdot (z_{1}-z_{2}) \right]$

$\rho\cdot v_{2}^{2} = 2\cdot (P_{1}-P_{2})+\rho\cdot [v_{1}^{2}+2\cdot g\cdot (z_{1}-z_{2})]$

$v_{2}^{2}= \frac{2\cdot (P_{1}-P_{2})}{\rho}+v_{1}^{2}+2\cdot g\cdot (z_{1}-z_{2})$

$v_{2} = \sqrt{\frac{2\cdot (P_{1}-P_{2})}{\rho}+v_{1}^{2}+2\cdot g\cdot (z_{1}-z_{2}) }$ (2)

If we know that $P_{1}-P_{2} = 0\,Pa$ , $\rho=1000\,\frac{kg}{m^{3}}$ , $v_{1} = 15.5\,\frac{m}{s}$ , $g = 9.807\,\frac{m}{s^{2}}$ and $z_{1}-z_{2} = -3.5\,m$ , then the speed of the water flow in the pipe on the second floor is:

$v_{2}=\sqrt{\left(15.5\,\frac{m}{s} \right)^{2}+2\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (-3.5\,m)}$

$v_{2} \approx 13.100\,\frac{m}{s}$

The speed of the water flow in the pipe on the second floor is approximately 13.1 meters per second.

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2 years ago

The resistance of a 24 W, 12 V filament lamp depends on the current flowing through the lamp. For currents up to 0.8 A, the resi

Harman [31]

Answer:

V=IR

V=0.8×2.5

V=2V

where V=potential difference

I=Current

R=Resistance

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2 years ago

Which statement is TRUE? Group of answer choices a) An object that is slowing down while traveling in the negative x-direction a

slava [35]

Answer:

d) An object that is speeding up always has a positive acceleration, regardless of the direction it travels.

Explanation:

a ) a) An object that is slowing down while traveling in the negative x-direction always has a positive acceleration.

It has negative acceleration in the negative x-direction.

b) An object that is speeding up while traveling in the negative x-direction always has a positive acceleration.

It has a positive acceleration in the negative x-direction'

c) An object that is slowing down always has a negative acceleration, regardless of the direction it travels.

It has a positive acceleration in opposite direction.

e ) An object that is slowing down always has a positive acceleration, regardless of the direction it travels.

It has a positive acceleration only in opposite direction .

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2 years ago

Is energy made or lost over time

Ann [662]

Well basically in physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant, it is said to be conserved over time. This law means that energy can neither be created nor destroyed, it can only be transformed or transferred from one form to another.

Hope this helps (:

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3 years ago