If the density of an object is 30 g/cm3 and its volume is 10 cm3, what is its mass in grams?

A machine is designed to lift an object with a weight of 12 newtons. if the input force for the machine is setat 4 newtons, what

Alja [10]

Hope this helps you!

4 0

3 years ago

Assume that, when we walk, in addition to a fluctuating vertical force, we exert a periodic lateral force of amplitude 25 NN at

dexar [7]

Complete Question

The complete question is shown on the first uploaded image

Answer:

Explanation:

From the question we are told

The amplitude of the lateral force is $F = 25 \ N$

The frequency is $f = 1 \ Hz$

The mass of the bridge per unit length is $\mu = 2000 \ kg /m$

The length of the central span is $d = 144 m$

The oscillation amplitude of the section considered at the time considered is $A = 75 \ mm = 0.075 \ m$

The time taken for the undriven oscillation to decay to $\frac{1}{e}$ of its original value is t = 6T

Generally the mass of the section considered is mathematically represented as

$m = \mu * d$

=> $m = 2000 * 144$

=> $m = 288000 \ kg$

Generally the oscillation amplitude of the section after a time period t is mathematically represented as

$A(t) = A_o e^{-\frac{bt}{2m} }$

Here b is the damping constant and the $A_o$ is the amplitude of the section when it was undriven

So from the question

$\frac{A_o}{e} = A_o e^{-\frac{b6T}{2m} }$

=> $\frac{1}{e} =e^{-\frac{b6T}{2m} }$

=> $e^{-1} =e^{-\frac{b6T}{2m} }$

=> $-\frac{3T b}{m} = -1$

=> $b = \frac{m}{3T}$

Generally the amplitude of the section considered is mathematically represented as

$A = \frac{n * F }{ b * 2 \pi }$

=> $A = \frac{n * F }{ \frac{m}{3T} * 2 \pi }$

=> $n = A * \frac{m}{3} * \frac{2\pi}{25}$

=> $n = 0.075 * \frac{288000}{3} * \frac{2* 3.142 }{25}$

=> $n = 1810 \ people$

3 0

3 years ago

Which number should be placed in the blank to make the equation balance? 3 H2+ N2 --- ______ NH3

miv72 [106K]

2 should be placed in the blank to make the equation balance. Btw, that's chemistry and not physics. Get it right.

7 0

3 years ago

Which sentence explains why optical land telescopes are not able to take images as clear as those taken by the Hubble Space Tele

ad-work [718]

he Hubble Space Telescope has beamed hundreds of thousands of images back to Earth over the past two decades. One might call it the most skilled paparazzo, snapping countless images of the stars.

Thanks to these images, scientists have been able to determine the age of the universe and shed light on the existence of dark energy. These extraordinary advancements have been possible because the Hubble images surpass those taken by Earth-based telescopes.

While ground-based observatories are usually located in highly elevated areas with minimal light pollution, they must contend with atmospheric turbulence, which limits the sharpness of images taken from this vantage point. (The effects of atmospheric turbulence are clear to anyone looking at the stars ? this is why they appear to twinkle.)

In space, however, telescopes are able to get a clearer shot of everything from exploding stars to other galaxies.

Another disadvantage for ground-based telescopes is that the Earth's atmosphere absorbs much of the infrared and ultraviolet light that passes through it. Space telescopes can detect these waves.

Newer ground-based telescopes are using technological advances such as adaptive optics to try to correct or limit atmospheric distortion, but there's no way to see the wavelengths that the atmosphere blocks from reaching Earth, according to the Space Telescope Science Institute (STScI), which manages the Hubble research program.

One downside to space telescopes like the Hubble is that they are extremely difficult to maintain and upgrade. The Hubble is the first telescope specifically designed to be repaired in space by astronauts, while other space telescopes cannot be serviced at all.

NASA scientists estimate that the telescope will only be able to keep taking pictures for five more years.

7 0

3 years ago

Read 2 more answers

if mass of an object is decreased to half and acting force is reduced by quarter the acceleration of its motion

11111nata11111 [884]

Answer:

See explanations below

Explanation:

According to Newtons second law of motion

F = mass * acceleration

F = ma

If mass of an object is decreased to half, then m₂ = 1/2 m

If acting force is reduced by quarter, then F₂ = 3/4 F

F₂ = m₂a₂

3/4F = 1/2m a₂

Divide both expressions

(3/4F)/F = (1/2m)a₂/ma

3/4 = 1/2a₂/a

3/4 = a₂/2a

4a₂ = 6a

2a₂ = 3a

a₂ = 3/2 a

Hence the acceleration of its motion will be one and a half of its original acceleration.

8 0

3 years ago