All categories

3 years ago

When is work performed?

1 answer:

7 0

Answer: In summary, work is done when a force acts upon an object to cause a displacement. Three quantities must be known in order to calculate the amount of work. Those three quantities are force, displacement and the angle between the force and the displacement.

Explanation:

You might be interested in

Prove(show) ''T=2π√(l/g)''

Nonamiya [84]

Answer:

Time period for Simple pendulum, $T=2\pi\sqrt{\frac{l}{g}$

Explanation:

The Simple Pendulum

Consider a small bob of mass $m$ is tied to extensible string of length $l$ that is fixed to rigid support. The bob is oscillating in the plane about verticle.

Let $\theta$ is the angle made by string with vertical during oscillation.

Vertical component of the force on bob, $F=-mg\sin\theta$

Negative sign shows that its opposing the motion of bob.

Taking $\theta$ as very small angle then, $\sin\theta\sim\theta$

$F=-mg\theta$

Let $x$ is the displacement made by bob from its mean position ,

then, $\theta=\frac{x}{l}$

so, $F=-mg\frac{x}{l}$ ........(1)

Since, pendulum is in hormonic motion,

as we know, $F=-kx$

where $k$ is the constant and $k=m\omega^{2}$

$F=-m\omega^2x$ .........(2)

From equation (1) and (2)

$-m\omega^2x=-mg\frac{x}{l}$

$\omega=\sqrt{\frac{g}{l}}$

Since, $\omega=\frac{2\pi}{T}$

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

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

6 0

3 years ago

Carbon has six protons. Which model shows a neutral atom of carbon?

MatroZZZ [7]

Explanation:

Neutral carbon-12 (or any carbon atom) has 6 electrons with a total negative charge of 6e- orbiting a nucleus with a total positive charge of 6e+, so that the total net charge is zero. The nucleus is made up of 6 protons, each with a positive charge of e+, and 6 neutrons, each with zero charge.

4 0

2 years ago

Identify the theory that can be used to explain each phenomenon.

ahrayia [7]

Answer:

Diffraction: Wave Theory

Interference: Wave Theory

Reflection: both particles and wave theories

Refraction: both particles and wave theories

3 0

3 years ago

A 2 kg picture frame sits on a shelf at a height of 0.5 m. how much gravitational potential energy is added to the picture frame

AysviL [449]

The change in gravitational potential energy is A) 15.68 J

Explanation:

The gravitational potential energy of an object is the energy possessed by the object due to its position in the gravitational field.

The change in gravitational potential energy of an object is given by the equation:

$\Delta U = mg\Delta h$

where

m is the mass of the object

$g=9.8 m/s^2$ is the acceleration due to gravity

$\Delta h$ is the change in height of the object

In this problem, we have

m = 2 kg is the mass of the frame

$\Delta h = 1.3 - 0.5 = 0.8 m$ is the change in height

Substituting, we find:

$\Delta U = (2)(9.8)(0.8)=15.68 J$

Learn more about potential energy:

brainly.com/question/1198647

brainly.com/question/10770261

#LearnwithBrainly

7 0

3 years ago

You are explaining to friends why astronauts feel weightless orbiting in the space shuttle, and they respond that they thought g

bezimeni [28]

Answer:

It's only 1.11 m/s2 weaker at 400 km above surface of Earth

Explanation:

Let Earth radius be 6371 km, or 6371000 m. At 400km above the Earth surface would be 6371 + 400 = 6771 km, or 6771000 m

We can use Newton's gravitational law to calculate difference in gravitational acceleration between point A (Earth surface) and point B (400km above Earth surface):

$g = G\frac{M}{r^2}$

where G is the gravitational constant, M is the mass of Earth and r is the distance form the center of Earth to the object

$\frac{g_B}{g_A} = \frac{GM/r^2_B}{GM/r^2_A}$

$\frac{g_B}{g_A} = \left(\frac{r_A}{r_B}\right)^2$

$\frac{g_B}{g_A} = \left(\frac{6371000}{6771000}\right)^2$

$\frac{g_B}{g_A} = 0.94^2 = 0.885$

$g_B = 0.885 g_A$

So the gravitational acceleration at 400km above surface is only 0.885 the gravitational energy at the surface, or 0.885*9.81 = 8.7 m/s2, a difference of (9.81 - 8.7) = 1.11 m/s2.

6 0

3 years ago