7. A student is rotating an object on a rope that is 4.5m long. If we increase the length

The ideal mechanical advantage of a machine reflects the increase or decrease in force there world be without friction, it is al

brilliants [131]

True: the ideal mechanical advantage of a machine is always greater than the actual mechanical advantage because all machines must overcome friction.

Explanation:

For a simple machine, it is possible to calculate two types of mechanical advantage:

1) The Ideal Mechanical Advantage (IMA) is given by

$IMA=\frac{d_e}{d_r}$

where

$d_r$ is the resistance arm

$d_e$ is the effort arm

The IMA gives the mechanical advantage of the machine if there are no friction forces acting on it, and if all the work in input is converted into work in output with no loss of energy

2) The Actual Mechanical Advantage (AMA) is given by

$AMA=\frac{L}{E}$

where

L is the load (the force in output)

E is the effort (the force in input)

The AMA gives the real mechanical advantage of the machine. For an ideal machine,

$AMA=IMA$

Because there is no loss of energy due to friction.

For a real machine instead,

$AMA$

because part of the input energy is converted into thermal energy and other forms of energy due to the presence of friction, so it is "wasted" energy.

Learn more about levers and machines:

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8 0

3 years ago

How is the direction of light changed when it travels from an optically denser medium to an optically rarer medium????? please a

ANTONII [103]

Answer:

The light bends away from the normal

Explanation:

We can solve the problem by using Snell's law:

$n_1 sin \theta_1 = n_2 sin \theta_2$

where:

$n_1$ is the index of refraction of the first medium

$n_2$ is the index of refraction of the second medium

$\theta_1$ is the angle of incidence (angle between the incoming ray and the normal to the interface)

$\theta_2$ is the angle of refraction (angle between the outcoming ray and the normal to the interface)

We can rearrange the equation as

$sin \theta_2 = \frac{n_1}{n_2}sin \theta_1$

In this problem, light travels from an optically denser medium to an optically rarer medium, so

$n_1 > n_2$

Therefore, the term $\frac{n_1}{n_2}$ is greater than 1, so

$sin \theta_2 > sin \theta_1\\\rightarrow \theta_2 > \theta_1$

which means that the angle of refraction is greater than the angle of incidence, and so the light will bend away from the normal.

4 0

3 years ago

Un movil aumenta su velocidad de 10m/s a 20m/s acelerando uniformemente a razon de 5m/s2 ¿que distancia logro en dicha operacion

Kruka [31]

v₀ = initial velocity of the mobile = 10 m/s

v = final velocity of the mobile = 20 m/s

a = acceleration of the mobile = 5 m/s²

d = distance traveled during this operation = ?

Using the kinematics equation

v² = v²₀ + 2 a d

inserting the above values in the equation

20² = 10² + 2 (5) d

400 = 100 + 10 d

subtracting 100 both side

400 - 100 = 100 - 100 + 10 d

300 = 10 d

dividing both side by 10

300/10 = 10 d/10

d = 30 m

hence mobile travels 30 m.

8 0

3 years ago

At sunset, red light travels horizontally through the doorway in the western wall of your beach cabin, and you observe the light

Nady [450]

Answer:

$9.8\cdot 10^{-6}m$

Explanation:

For light passing through a single slit, the position of the nth-minimum from the central bright fringe in the diffraction pattern is given by

$y=\frac{n \lambda D}{d}$

where

$\lambda$ is the wavelength

D is the distance of the screen from the slit

d is the width of the slit

In this problem, we have

$\lambda=700 nm = 7.00\cdot 10^{-7}m$ is the wavelength of the red light

D = 14 m is the distance of the screen from the doorway

d = 1.0 m is the width of the doorway

Substituting n=1 into the equation, we find the distance between the central bright fringe and the first-order dark fringe (the first minimum):

$y=\frac{(1)(7.00\cdot 10^{-7} m)(14 m)}{1.0 m}=9.8\cdot 10^{-6}m$

6 0

3 years ago

How do i exist (serious question, i'm in the dark abyss of nothing please help)

Reptile [31]

The only evidence you have that you exist as a self-aware being is your conscious experience of thinking about your existence. Beyond that you're on your own. You cannot access anyone else's conscious thoughts, so you will never know if they are self-aware.

3 0

2 years ago