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3 years ago

Tracy scuffs her socked feet across a carpet. When she touches a doorknob, she gets a small shock.

Physics

2 answers:

lubasha [3.4K]3 years ago

6 0

I believe the answer would be B.

Brut [27]3 years ago

6 0

Answer:

Correct answer is b(Through friction between her feet and the carpet)

Explanation:

Whenever we rub our body against carpet or any other object made of fiber materials that time frictional force act. Due to frictional force our body get some extra electron.

When Tracy scuff her feet across a carpet, That time due to friction between her feet and carpet she got some extra electrons. These Electrons can move easily through conductor. When Tracy touched the doorknob which is made up of some metal(conductor) and has positive charge that time extra electrons moved from Tracy to the knob. Due to quick movement of electrons Tracy gets a small shock.

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What does more damage; a slow semi truck, or a fast sports car

Goshia [24]

The fast sports car does more damage then the slow semi truck

7 0

2 years ago

A food department is kept at â12Â°c by a refrigerator in an environment at 30Â°c. the total heat gain to the food department is

slava [35]

As per energy conservation in the reversible engine we can say

$Q_2 + W = Q_1$

here we know that

$Q_2 = 3300 kJ/h$

$Q_1 = 4800 kJ/h$

now from above equation

$3300 + W = 4800$

$W = 1500 kJ/h$

now we can convert it into kW

$W = 1500\times \frac{kJ}{3600s}$

$W = 0.42 kW$

so above is the power input to the refrigerator

now to find COP we know that

$COP = \frac{Q_2}{W}$

$COP = \frac{3300}{1500} = 2.2$

so COP of refrigerator is 2.2

3 0

2 years ago

Red light of wavelength 630 nm passes through two slits and then onto a screen that is 1.4 m from the slits. The center of the 3

VARVARA [1.3K]

Answer:

Part a)

$f = 4.76 \times 10^{14} Hz$

Part b)

$d = 3.48 \times 10^{-4} m$

Part c)

$\theta = 0.311 degree$

Explanation:

Part a)

As we know that the speed of light is given as

$c = 3 \times 10^8 m/s$

$\lambda = 630 nm$

now the frequency of the light is given as

$f = \frac{c}{\lambda}$

so we have

$f = \frac{3 \times 10^8}{630 \times 10^{-9}}$

$f = 4.76 \times 10^{14} Hz$

Part b)

Position of Nth maximum intensity on the screen is given as

$y_n = \frac{n\lambda L}{d}$

so here we know for 3rd order maximum intensity

$y_3 = 0.76 cm$

n = 3

L = 1.4 m

$0.76 \times 10^{-2} = \frac{3(630 \times 10^{-9})(1.4)}{d}$

$d = 3.48 \times 10^{-4} m$

Part c)

angle of third order maximum is given as

$d sin\theta = 3 \lambda$

$3.48 \times 10^{-4} sin\theta = 3(630 \times 10^{-9})$

$\theta = 0.311 degree$

8 0

2 years ago

A wave has a wavelength of 30 mm and a frequency of 5.0 hertz. What is its speed?

Alenkinab [10]

   Wave speed = (frequency) x (wavelength)

   = (5 / second) x (30 mm)

   = 150 mm/second = 0.15 meter/second .

8 0

2 years ago

A 1.00-kg mass is attatched to a string 1.0m long and completes a horizontal circle in 0.25s. What is the centripetal accelerati

liraira [26]

-- The string is 1 m long. That's the radius of the circle that the mass is
traveling in. The circumference of the circle is (π) x (2R) = 2π meters .

-- The speed of the mass is (2π meters) / (0.25 sec) = 8π m/s .

-- Centripetal acceleration is V²/R = (8π m/s)² / (1 m) = 64π^2 m/s²

-- Force = (mass) x (acceleration) = (1kg) x (64π^2 m/s²) =

64π^2 kg-m/s² = 64π^2 N = about <span>631.7 N .

</span>That's it. It takes roughly a 142-pound pull on the string to keep
1 kilogram revolving at a 1-meter radius 4 times a second !<span>
</span>If you eased up on the string, the kilogram could keep revolving
in the same circle, but not as fast.

You also need to be very careful with this experiment, and use a string
that can hold up to a couple hundred pounds of tension without snapping.
If you've got that thing spinning at 4 times per second and the string breaks,
you've suddenly got a wild kilogram flying away from the circle in a straight
line, at 8π meters per second ... about 56 miles per hour ! This could definitely
be hazardous to the health of anybody who's been watching you and wondering
what you're doing.

3 0

3 years ago