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3 years ago

Four-wheel drive trucks do not stop better on icy

Physics

1 answer:

MaRussiya [10]3 years ago

8 0

It would be Newton’s second law of motion

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The physical property that determines that how easily heat and electricity pass through a material is?

Varvara68 [4.7K]

Answer: Hello! I'm Jungkook. Here is your answer.....

A. conductivity

Explanation:

Hope this helps! Anneyong/Bye!

xoxoKookie

6 0

2 years ago

A bug flying horizontally at 0.65 m/s collides and sticks to the end of a uniform stick hanging vertically. After the impact, th

irina [24]

The angular momentum is defined as,

$L=I\omega$

Acording to this text we know for conservation of angular momentum that

$L_i=L_f$

Where $L_i$ is initial momentum

$L_f$ is the final momentum

How there is a difference between the stick mass and the bug mass, we define that

Mass of the bug= m

Mass of the stick=10m

At the point 0 we have that,

$L_i=mvl$

Where l is the lenght of the stick which is also the perpendicular distance of the bug's velocity

vector from the point of reference (O), and ve is the velocity

At the end with the collition we have

$L_f=(I_b+I_s)\omega$

Substituting

$L_f=(ml^2+\frac{10ml^2}{3})\omega$

$L_f=\frac{13}{10}ml^2w$

$m(0.65)l=\frac{13}{10}ml^2 \omega$

$\omega=\frac{1}{2l}$

Applying conservative energy equation we have

$\frac{1}{2}(I_b+I_s)\omega^2=mgh+10mgh'$

$\frac{1}{2}(ml^2+\frac{10ml^2}{3})(\frac{1}{2l})^2=mg(l-lcos\theta)+\frac{10}{2}mg(l-lcos\theta)$

Replacing the values and solving

$l=\frac{13}{0.54g}$

Substituting

l=\frac{13}{0.54(9.8)}

$l=2.45cm$

7 0

4 years ago

What is the resistance of a 7 W light bulb connected to a 7 V battery source. The answer key says .39 but not sure how they got

Kitty [74]

Explanation:

Power is current times voltage.

P = IV

And from Ohm's law, voltage is current times resistance.

V = IR

So if we solve for I in Ohm's law and substitute into the power equation:

I = V/R

P = (V/R) V

P = V² / R

Given that P = 7 W and V = 7 V:

7 = 7² / R

R = 7 Ω

Make sure you copied the problem correctly. If you did, the answer key may be wrong.

3 0

4 years ago

1) Find the voltage on a circuit with a resistance of 12.5 Ω if it has a current of 2.35 A.

KengaRu [80]

1. The voltage on the circuit with a resistance of 12.5 Ω and current of 2.35 A is 29.4 V.

2.The resistance in the circuit is found to be 1.45 Ω.

3. The equivalent resistance of the resistors connected in series is 24 Ω.

4. The equivalent resistance of the resistors connected in parallel is 2.18Ω.

5. The power generated is 552.5 W.

6. The frequency of the green light is 0.56×10¹⁵ Hz.

Explanation:

1) This problem can be solved using Ohm's law. Here the resistance (R) of the circuit is given to be 12.5 Ω and the current (I) is stated to be 2.35 A. So the ohm's law states that in a closed circuit, the voltage will be directly proportional to the current flowing in the circuit and the resistance will act as the proportionality constant.

$V = I * R = 2.35*12.5 = 29.4 V$

So, the voltage on the circuit with a resistance of 12.5 Ω and current of 2.35 A is 29.4 V.

2) Using the same Ohms' law, now we have to determine the resistance. So in this case, the voltage is given as 9 V and the current is said to be 6.2 A, then resistance can be determined as the ratio of voltage to current.

$R = \frac{V}{I} =\frac{9}{6.2} =1.45 Ohms$

So, the resistance in the circuit is found to be 1.45 Ω.

3) Here, the resistances of three resistors are given as 4 Ω, 8 Ω and 12 Ω. And it is stated that the resistances are connected or wired in series. Then the equivalent resistance will be obtained by the sum of resistances of three resistors, as the current flow will be constant in all the three resistors.

$R_{s} = R_{1} + R_{2} + R_{3} \\ \\R_{s} = 4+8+12 = 24 ohms$

Thus, the equivalent resistance of the resistors connected in series is 24 Ω.

4) Now, if the resistors are connected in parallel, then the equivalent resistance will be ratio of product of resistances to the sum of the resistances.

$\frac{1}{R_{p} }= \frac{1}{R_{1} } + \frac{1}{R_{2} } +\frac{1}{R_{3} }\\\\\frac{1}{R_{p} }=\frac{1}{4}+ \frac{1}{8} +\frac{1}{12} = \frac{6+3+2}{24} =\frac{11}{24} \\\\R_{p} = \frac{24}{11 } =2.18 Ohm$

Thus, the equivalent resistance of the resistors connected in parallel is 2.18Ω.

5) Power generated by the person can be obtained by the ratio of work done by the person to the time in which the work is done. So the work done can be obtained by the product of force with displacement.

As here the weight lifted by the person will act as dominant force on the person. So the force is considered as F = 956 N and the displacement is d = 2.41 m, then

$Work done = Force * displacement = 956*2.41 =2303.96 J$

So, the work done is obtained as 2303.96 J and the time is given as 4.17 s, then

$Power = \frac{Work done}{Time} =\frac{2303.96}{4.17} =552.5 W$

So, the power generated is 552.5 W.

6) In this, the wavelength of green light is given as 5.34 × 10⁻⁷ m. It is known that the wavelength is inversely proportional to the frequency.

$Wavelength = \frac{Speed of light}{Frequency}$

As, speed of light is known as 3×10⁸ m/s, the frequency will be determined as the ratio of speed of light to wavelength.

$Frequency = \frac{Speed of light}{Wavelength} =\frac{3*10^{8} }{5.34*10^{-7} } \\\\Frequency =0.56*10^{15} Hz$

Thus, the frequency of the green light is 0.56×10¹⁵ Hz.

8 0

4 years ago

A proton, mass 1.67 × 10−27 kg and charge +1.6 × 10−19 c, moves in a circular orbit perpendicular to a uniform magnetic field of

stellarik [79]

Time taken by proton to complete one complete circular orbit= 7.28 x 10⁻⁸ s

Explanation:

For proton, the centripetal force required for circular motion is provided by the magnetic force,

so Fm= Fc

q v B = m v²/r

m= mass of charged particle

v= velocity

B =magnetic field

q= charge

r= radius of circular path

v= q B r/m

now v= r ω

ω= angular velocity

ω r = q B r /m

ω=q B /m

now ω= 2π/T where T =time period

so 2π/T=q B/m

T= 2 πm/q B

T= 2π (1.67 x 10⁻²⁷)/ [( 1.6 x 10⁻¹⁹)* (0.9)]

T= 7.28 x 10⁻⁸ s

6 0

3 years ago