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3 years ago

Help me please i dont understand

Physics

1 answer:

solniwko [45]3 years ago

5 0

Answer:

It is b

Explanation:

The question tells you that the distance was increased 3 times the original distance, which means it was moved 3 times

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FLASH FLOODS CAN CAUSE VEHICLES TO FLOAT AND FILL WITH WATER, TRAPPING AND DROWNING PEOPLE. WHILE ESPECIALLY DANGEROUS AT NIGHT

levacccp [35]

Answer:

FLASH FLOODS CAN CAUSE VEHICLES TO FLOAT AND FILL WITH WATER, TRAPPING AND DROWNING PEOPLE. WHILE ESPECIALLY DANGEROUS AT NIGHT AND IN DEEP WATER, EVEN ____ INCHES OF WATER CAN FLOAT SOME SMALL CARS.

The Answer is SIX Inches.

Explanation:

Flash floods: are short-term events and are associated with short, high-intensity rainfall which occur when creeks that are normally dry fill up and other creeks overflow. Densely populated areas have a high risk of flash floods. Water levels in flash floods can rise one foot in five minutes making Six inches of water able to reach the bottom of most passenger cars. Moving water will exert pressure on a car. The car floats downstream when stream force exceeds the friction force, the car will be carried when bouyancy force (which is the upward force exerted by any fluid upon a body placed in it) is greater than vehicle weight.

8 0

3 years ago

A more realistic car would cause the wheels to spin in a manner that would result in the ground pushing it forward with a consta

bonufazy [111]

Answer:

acceleration = 22.14 m/s²

time = 2.80 s

Explanation:

given data

initial velocity = 31.0

final velocity =

time = 1.40

solution

we get here acceleration that is

acceleration = $\frac{v(final) - v(initial)}{t}$ ...............1

acceleration = $\frac{31-0}{1.40}$

acceleration = 22.14 m/s²

and

by kinematic equation of motion

v = u +at .........2

t = $\frac{62-0}{22.14}$

time = 2.80 s

8 0

4 years ago

A 21 kg chair initially at rest on a horizontal floor requires a 175 N horizontal force to set it in motion. Once the chair is i

Alika [10]

Answer: $\mu =0.85$

Explanation:

Given

mass of chair m=21 kg

Force required to set chair in motion is 175 N

Once the chair is in motion 137 N is require to move it with constant velocity

i.e. 175 N is the amount of force needed to just overcome static friction and 137 is the kinetic friction force

thus

$f_s(static\ friction)=\mu \cdot N$

where $\mu$ is the coefficient of static friction and N is Normal reaction

$N=mg$

$f_s=\mu mg$

$\mu mg=175$

$\mu =\frac{175}{21\times 9.8}$

$\mu =0.85$

8 0

3 years ago

Can someone help me??

Dmitry_Shevchenko [17]

Answer:

Bones

Explanation:

There is no explanation

4 0

3 years ago

A composite load consists of three loads connected in parallel. One draws 100 W at a PF of 0.92 lagging, another takes 250 W at

fenix001 [56]

Answer:

a) $I_{RMS} = 4.79 A$

b) $PF = 0.908$

Explanation:

Get the reactive powers for each of the loads:

Reactive power = Real Power * tanθ

For load 1

Active power, P₁ = 100 W

Power factor, $cos \theta_{1} = 0.92$

$\theta_{1} = cos^{-1} 0.92\\\theta_{1} = 23.074$

$Q_{1}= P_{1} tan \theta_{1} \\Q_{1}= 100tan 23.074\\Q_{1}= 42.60 W$

For load 2

Active power, P₂ = 250 W

Power factor, $cos \theta_{2} = 0.8$

$\theta_{2} = cos^{-1} 0.8\\\theta_{2} = 36.87$

$Q_{2}= P_{1} tan \theta_{2} \\Q_{2}= 250tan 36.87\\Q_{2}= 187.5 W$

For load 3

Active power, P₃ = 250 W

Power factor, $cos \theta_{3} = 1$

$\theta_{3} = cos^{-1} 1\\\theta_{3} =0$

$Q_{2}= P_{1} tan \theta_{3} \\Q_{3}= 150tan 0\\Q_{3}= 0 W$

Calculate the total reactive power, $Q_{net} = 42.6 + 187.5 + 0$

$Q_{net} = 230.1 W$

Calculate the total active power, $P_{net} = 100 + 250 + 150 = 500 W$

$S_{net} = P_{net} + Q_{net} \\S_{net} = 500 + j230.1$

$P_{net} = IVcos \theta_{net}$

$\theta_{net} = tan^{-1} \frac{230.1}{500} \\\theta_{net} = 24.712$

V = 115 $V_{rms}$

$500 = I_{RMS} * 115 cos 24.712\\I_{RMS} = 500/104.47\\ I_{RMS} = 4.79 A$

b) Power factor of the composite load is $cos\theta_{net}$

$\theta_{net} = 24.712\\PF = cos 24.712\\PF = 0.908$

4 0

3 years ago