What is the force of a 100 kg car that hits a wall while accelerating at 5 m/s2?

If a woman needs an amplification of 1.0 ✕ 105 times the threshold intensity to enable her to hear at all frequencies, what is h

Damm [24]

Answer:

50 dB.

Explanation:

given,

Amplification needed by the woman,I= 1 x 10⁵ I₀

where as I₀ is the threshold frequency

overall hearing loss of the woman= ?

Using the equation of sound intensity level

$\beta(dB) = 10 log(\dfrac{I}{I_0})$

$\beta(dB) = 10 log(\dfrac{1\times 10^5\ I_0}{I_0})$

$\beta(dB) = 10 log(1\times 10^5)$

$\beta(dB) = 50\ dB$

The overall hearing loss of woman is equal to 50 dB.

7 0

4 years ago

100 Points

solniwko [45]

Answer:

4) Isaac Newton was the first scientist to propose the idea that gravity increases distance between objects decrease

Explanation:

1 - Kepler may have inspired most of Newton's propositions, but there is no record of collaborating on the theory of universal gravitation.

2 - The universal gravitation theory resemble the works of other great scientists, but Newton was indeed the first to propose this idea of gravitation

3 - On the contrary, these scientists have shared concepts, with differences in accuracy that supersede each other to be accepted by the community (i.e: Einstein being at the forefront despite sharing some ideas with Newton)

8 0

3 years ago

A small laser used as a pointer produces a beam of red light 5 mm in diameter, and has a power output of 5 milliwatts. What is t

Nata [24]

Answer:

434.0 V/m

Explanation:

The power output of the laser is:

$P=5 mW = 0.005 W$

while the radius of the beam is

$r=\frac{5 mm}{2}=2.5 mm = 0.0025 m$

so the cross-sectional area is

$A=\pi r^2 = \pi (0.0025 m)^2=2.0\cdot 10^{-5} m^2$

So the intensity of the laser beam is

$I=\frac{P}{A}=\frac{0.005 W}{2.0\cdot 10^{-5} m^2}=250 W/m^2$

The intensity of a laser beam is related to the magnitude of the electric field by

$I=\frac{1}{2}c\epsilon_0 E^2$

where

c is the speed of light

$\epsilon_0$ is the vacuum permittivity

Solving the formula for E, we find

$E=\sqrt{\frac{2I}{c\epsilon_0}}=\sqrt{\frac{2(250 W/m^2)}{(3\cdot 10^8 m/s)(8.85\cdot 10^{-12} F/m)}}=434.0 V/m$

4 0

3 years ago

Drag and drop the terms at the left to match the appropriate descriptions at the right. ResetHelp Visual acuity Emmetropia Accom

Lubov Fominskaja [6]

Answer: Visual acuity: sharpness of vision.

Myopia: nearsightedness

Refraction: bending of light rays.

Emmetropia: normal vision.

Accommodation: changes the shape of the eye lens to focus light on the retina.

Presbyopia: age-related farsightedness due to loss of elasticity in the lens.

Astigmatism: reduction in visual acuity due to changes in the cornea or lens.

Hyperopia: farsightedness

Myopia and hyperopia are refractive errors of the eye.

Presbyopia occurs in old age people.

Explanation:

Visual acuity: It can be defined as the inability to observe the details of shape of the object. Person loses sharpness in vision.

Myopia: It is a defect in vision in which person is able to observe the near by objects clearly but not able to see the distant objects.

Refraction: It can be defined as the bending of beam of light when it passes through from one substance to another.

Emmetropia: It is a vision without any defect.

Accommodation: It is the ability of the eye to adjust its focal length and adjusting the light on focus.

Presbyopia: It can be defined as the loss of ability of eye to focus on the object. It occurs in old age.

Astigmatism: It is a refractive error in which the eye does not focus light on retina.

Hyperopia: It is also called as farsightedness. Distant objects can be seen clearly but nearby appears blurry.

5 0

3 years ago

A wire has a current density of 6.25 × 10 6 A / m 2 6.25×106 A/m2 . If the cross-sectional area of the wire is 1.79 mm 2 1.79 mm

joja [24]

Answer:17.44A

Explanation: Current density=I/Area

Area is given by 2.79mm^2=2.79×10^-6m^2

Current=I=current density ×Area=6.25×10^6 ×2.79×10^-6=17.44A

3 0

3 years ago

What is the force of a 100 kg car that hits a wall while accelerating at 5 m/s2?​

What is the force of a 100 kg car that hits a wall while accelerating at 5 m/s2?