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2 years ago

11

one of the ways, covered in the article and in class, that we charged an object was rubbing it against carpet on the floor true

or false the answers

1 answer:

astraxan [27]2 years ago

5 0

Answer:

It is possible to statically charge objects by rubbing it against carpet fibers, but I'm not sure if that was in the article that you read.

Explanation:

Static charge can build up via carpet fibers.

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Where is each subatomic particle is found in an atom

Ronch [10]

Protons and neutrons are located in the nucleus, a dense central core in the middle of the atom, while the electrons are located outside the nucleus.

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3 years ago

A converging lens of focal length 20 cm is placed in contact with a diverging lens of focal length 30 cm. The focal length of th

kramer

Answer:

The focal lenth (F) =+10.0cm

Explanation:

The formular for combined focal length (F) is given as;

$1/f = 1/f_{1} + 1/f_{2}$

In this question,

F1 = 20cm

F2 = -30cm

Plugging the values into the formuar above,

$1/f = 1/20 + 1/(-30)$

$1/f = 0.05 - 0.033[tex]1/f = -0.017f = [tex]1/ -0.017$

f = 58.82cm

i.e. the combination behaves as a converging lens (because of the postive sign) of focal length 58.82cm .

7 0

3 years ago

The orientation of which of the following does not influence the phases of the moon? a. Earth c. Sun b. the moon d. Stars Please

beks73 [17]

I'm pretty sure it's D. The stars don't influence the moon's phases.

6 0

3 years ago

A railroad car moves under a grain elevator at a constant speed of 3.20 m/s. Grain drops into the car at the rate of 240 kg/min.

dedylja [7]

Answer:

F = 768 N

Explanation:

It is given that,

Speed of the elevator, v = 3.2 m/s

Grain drops into the car at the rate of 240 kg/min, $\dfrac{dm}{dt}=240\ kg/min = 4\ kg/s$

We need to find the magnitude of force needed to keep the car moving constant speed. The relation between the momentum and the force is given by :

$F=\dfrac{dp}{dt}$

$F=m\dfrac{dv}{dt}+v\dfrac{dm}{dt}$

Since, the speed is constant,

$F=m\dfrac{dv}{dt}$

$F=v\dfrac{dm}{dt}$

$F=3.2\times 240$

F = 768 N

So, the magnitude of force need to keep the car is 768 N. Hence, this is the required solution.

5 0

3 years ago

If the range of a projectile's trajectory is six times larger than the height of the trajectory, then what was the angle of laun

zvonat [6]

Answer:

H = 1/2 g t^2 where t is time to fall a height H

H = 1/8 g T^2 where T is total time in air (2 t = T)

R = V T cos θ horizontal range

3/4 g T^2 = V T cos θ 6 H = R given in problem

cos θ = 3 g T / (4 V) (I)

Now t = V sin θ / g time for projectile to fall from max height

T = 2 V sin θ / g

T / V = 2 sin θ / g

cos θ = 3 g / 4 (T / V) from (I)

cos θ = 3 g / 4 * 2 sin V / g = 6 / 4 sin θ

tan θ = 2/3

θ = 33.7 deg

As a check- let V = 100 m/s

Vx = 100 cos 33.7 = 83,2

Vy = 100 sin 33,7 = 55.5

T = 2 * 55.5 / 9.8 = 11.3 sec

H = 1/2 * 9.8 * (11.3 / 2)^2 = 156

R = 83.2 * 11.3 = 932

R / H = 932 / 156 = 5.97 6 within rounding

3 0

2 years ago