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2 years ago

Select all the correct answers.

Physics

1 answer:

faltersainse [42]2 years ago

4 0

Answer:

so therefore, the comb gains electron and the hair losses electrons

Explanation:

It is known that electron contain a negative charge.

So, when an atom gain electrons then number of electrons within the atom increases. As a result, the atom acquires a negative charge.

But when an atom loses electrons, there will be deficiency of electrons within the atom. As a result, the atom becomes positively charged.

Hence,, when people use plastic combs on their hair, the combs become negatively charged. The situation which is true about this is the comb gains electrons and the hair loses electrons.

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A stone is thrown vertically into the air at an initial velocity of 96 ft/s. On Mars, the height s (in feet) of the stone above

vladimir1956 [14]

Answer:

240 ft

Explanation:

t = Time taken

u = Initial velocity = 96 ft/s

v = Final velocity

s = Displacement

a = Acceleration = 12 m/s² on Mars 32 ft/s² on Earth negative due to upward direction

Mars

$s=ut+\frac{1}{2}at^2\\\Rightarrow s=96\times t+\frac{1}{2}\times -12\times t^2\\\Rightarrow s=96t-6t^2\ ft$

Earth

$s=ut+\frac{1}{2}at^2\\\Rightarrow s=96\times t+\frac{1}{2}\times -32\times t^2\\\Rightarrow s=96t-16t^2\ ft$

Differentiating the first equation with respect to time we get

$\frac{ds}{dt}=96-12t$

Equating with zero

$0=96-12t\\\Rightarrow t=\frac{96}{12}=8\ s$

Differentiating the second equation with respect to time we get

$\frac{ds}{dt}=96-32t$

Equating with zero

$0=96-32t\\\Rightarrow t=\frac{96}{32}=3\ s$

Applying the time taken to the above equations, we get

$s=96t-6t^2\ ft\\\Rightarrow s=96\times 8-6\times 8^2\\\Rightarrow s=384$

$s=96t-16t^2\\\Rightarrow s=96\times 3-16\times 3^2\\\Rightarrow s=144$

Difference in height = 384-144 = 240 ft

The stone will travel 240 ft higher on Mars

6 0

2 years ago

) A satellite of mass m has an orbital period T when it is in a circular orbit of radius R around the earth. If the satellite in

Mrrafil [7]

Answer:

A) T.

Explanation:

Kepler's third law states that the orbital period (T) of a satellite is related with the radius (R) and the mass of the object (M) it orbits:

$T=\frac{2\pi R^{\frac{3}{2}}}{\sqrt{GM}}$

So the orbital period is independent of the mass of the satellite, that means no matter the mass every satellite at a radius R around the earth have an orbital period A.

4 0

3 years ago

Which statement about polymers is true?

Mamont248 [21]

Where are the statements? You forgot to attach them lol

6 0

3 years ago

Calculate the average linear momentum of a particle described by the following wavefunctions: (a) eikx, (b) cos kx, (c) e−ax2 ,

Maksim231197 [3]

Answer:

a) p=0, b) p=0, c) p= ∞

Explanation:

In quantum mechanics the moment operator is given by

p = - i h’ d φ / dx

h’= h / 2π

We apply this equation to the given wave functions

a) φ = $e^{ikx}$

.d φ dx = i k $e^{ikx}$

We replace

p = h’ k $e^{ikx}$

i i = -1

The exponential is a sine and cosine function, so its measured value is zero, so the average moment is zero

p = 0

b) φ = cos kx

p = h’ k sen kx

The average sine function is zero,

p = 0

c) φ = $e^{-ax^{2} }$

d φ / dx = -a 2x $e^{-ax^{2} }$

.p = i a g ’2x $e^{-ax^{2} }$

The average moment is

p = (p₂ + p₁) / 2

p = i a h ’(-∞ + ∞)

p = ∞

6 0

3 years ago

The filament of a certain lamp has a resistance that increases linearly with temperature. When a constant voltage is switched on

Neporo4naja [7]

Answer:

162.8 K

Explanation:

initial current = io

final current, i = io/8

Let the potential difference is V.

coefficient of resistivity, α = 43 x 10^-3 /K

Let the resistance is R and the final resistance is Ro.

The resistance varies with temperature

R = Ro ( 1 + α ΔT)

V/i = V/io (1 + α ΔT )

8 = 1 + 43 x 10^-3 x ΔT

7 = 43 x 10^-3 x ΔT

ΔT = 162.8 K

Thus, the rise in temperature is 162.8 K.

5 0

2 years ago