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3 years ago

Find the total electric charge of 2.5 kg of electrons. Express your answer using two significant figures.

Physics

1 answer:

zimovet [89]3 years ago

4 0

Answer : The total electric charge of electrons is, $-4.4\times 10^{11}C$

Explanation:

Answer : The number of electrons transferred are, $4.68\times 10^{20}$

Explanation :

First we have to calculate the number of electrons.

Number of electrons = $\frac{\text{Total mass of electrons}}{\text{Mass of one electron}}$

Mass of 1 electron = $9.1\times 10^{-31}kg$

Total mass of electron = 2.5 kg

Number of electrons = $\frac{2.5kg}{9.1\times 10^{-31}kg}$

Number of electrons = $2.75\times 10^{30}$

Now we have to calculate the total electric charge of electrons.

Formula used :

$Q=ne\\\\n=\frac{Q}{e}$

where,

n = number of electrons transferred = $2.75\times 10^{30}$

Q = charge on electrons = ?

e = charge on 1 electron = $-1.602\times 10^{-19}C$

Now put all the given values in the above formula, we get:

$2.75\times 10^{30}=\frac{Q}{-1.602\times 10^{-19}C}$

$Q=-4.4\times 10^{11}C$

Thus, the total electric charge of electrons is, $-4.4\times 10^{11}C$

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A small sphere with mass m is attached to a massless rod of length L that is pivoted at the top, forming a simple pendulum. The

USPshnik [31]

Answer:

a) see attached, a = g sin θ

c) v = √(2gL (1-cos θ))

Explanation:

In the attached we can see the forces on the sphere, which are the attention of the bar that is perpendicular to the movement and the weight of the sphere that is vertical at all times. To solve this problem, a reference system is created with one axis parallel to the bar and the other perpendicular to the rod, the weight of decomposing in this reference system and the linear acceleration is given by

Wₓ = m a

W sin θ = m a

a = g sin θ

b) The diagram is the same, the only thing that changes is the angle that is less

θ' = 9/2 θ

c) At this point the weight and the force of the bar are in the same line of action, so that at linear acceleration it is zero, even when the pendulum has velocity v, so it follows its path.

The easiest way to find linear speed is to use conservation of energy

Highest point

Em₀ = mg h = mg L (1-cos tea)

Lowest point

Emf = K = ½ m v²

Em₀ = Emf

g L (1-cos θ) = v² / 2

v = √(2gL (1-cos θ))

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3 years ago

What do folds on a strip of paper mean

Vlad [161]

There are creases. Or just origami

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2 years ago

A ball is attached to a string of length 3 m to make a pendulum. The pendulum is placed at a location that is away from the Eart

Musya8 [376]

1) $0.61 m/s^2$

2) 13.9 s

Explanation:

The acceleration due to gravity is the acceleration that an object in free fall (acted upon the force of gravity only) would have.

It can be calculated using the equation:

$g=\frac{GM}{r^2}$ (1)

where

G is the gravitational constant

$M=5.98\cdot 10^{24} kg$ is the Earth's mass

r is the distance of the object from the Earth's center

The pendulum in the problem is at an altitude of 3 times the radius of the Earth (R), so its distance from the Earth's center is

$r=4R$

where

$R=6.37\cdot 10^6 m$ is the Earth's radius

Therefore, we can calculate the acceleration due to gravity at that height using eq.(1):

$g=\frac{GM}{(4R)^2}=\frac{(6.67\cdot 10^{-11})(5.98\cdot 10^{24})0.}{(4\cdot 6.37\cdot 10^6)^2}=0.61 m/s^2$

The period of a simple pendulum is the time the pendulum takes to complete one oscillation. It is given by the formula

$T=2\pi \sqrt{\frac{L}{g}}$

where

L is the length of the pendulum

g is the acceleration due to gravity at the location of the pendulum

Note that the period of a pendulum does not depend on its mass.

For the pendulum in this problem, we have:

L = 3 m is its length

$g=0.61 m/s^2$ is the acceleration due to gravity (calculated in part 1)

Therefore, the period of the pendulum is:

$T=2\pi \sqrt{\frac{3}{0.61}}=13.9 s$

4 0

3 years ago

You want to get a Q-taco from stripes so you head 3 miles at 45 degrees S of E. What

Cloud [144]

Trigonometry allows finding the result for the decomposition of the displacement vector is:

x = 2.12 mi

y = -2.12 mi

Displacement is a vector quantity, which has modulus and direction.

The cardinal points are a reference system with respect to which measurements are made, this system is related to the Cartesian system with the East in the positive direction of the x-axis and the North with the positive direction of the y-axis.

In the attached we can see a diagram of the vector and its components, the indicated direction of 45 S of the E, in the Cartesian system where the angles are measured from the positive side of the x-axis in a counterclockwise direction is:

θ = 360 - 45

θ = 315º

Let's use trigonometry to decompose the vector d = 3 mi

cos 315 = $\frac{x}{d}$