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2 years ago

How is one kg mass defined in SI system

2 answers:

5 0

The kilogram, symbol kg, is the SI unit of mass. It is defined by taking the fixed numerical value of the Planck constant h to be 6.626 070 15 × 10-34 when expressed in the unit J s, which is equal to kg m2 s -1 , where the meter and the second are defined in terms of c and ∆νCs.

Artist 52 [7]2 years ago

4 0

Answer:

It is originally defined as the mass of one liter (10-3 cubic meter) of pure water.

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A compact car has a mass of 1380 kg . Assume that the car has one spring on each wheel, that the springs are identical, and that

astraxan [27]

Answer:

A) $k=34867.3384\ N.m^{-1}$

B) $\omega'\approx84\ Hz$

Explanation:

Given:

mass of car, $m=1380\ kg$

frequency of spring oscillation, $f=1.6\ Hz$

We knkow the formula for spring oscillation frequency:

$\omega=2\pi.f$

$\Rightarrow \sqrt{\frac{k_{eq}}{m} } =2\pi.f$

$\sqrt{\frac{k_{eq}}{1380} } =2\times \pi\times 1.6$

$k_{eq}=139469.3537\ N.m^{-1}$

Now as we know that the springs are in parallel and their stiffness constant gets added up in parallel.

<u>So, the stiffness of each spring is (as they are identical):</u>

$k=\frac{k_{eq}}{4}$

$k=\frac{139469.3537}{4}$

$k=34867.3384\ N.m^{-1}$

given that 4 passengers of mass 70 kg each are in the car, then the oscillation frequency:

$\omega'=\sqrt{\frac{k_{eq}}{(m+70\times 4)} }$

$\omega'=\sqrt{\frac{139469.3537}{(1380+280)} }$

$\omega'\approx84\ Hz$

7 0

4 years ago

After an ice storm, ice falls from one of the top floors of a 65-story building. The ice falls freely under the influence of gra

adell [148]

Answer:

The correct answer is a) The kinetic energy of the ice increases by equal amounts for equal distances.

Explanation:

The law of conservation states that the energy cannot be created nor be destroyed but can be converted from one form to another.Before the ice even starts falling we already know that it possesses energy in the form of potential energy given by P=mgh where m is the mass of the ice , g is the acceleration due to gravity and h is the height of the ice above the ground whatever that may be, since a number is not given here.As the ice falls the energy is converted from potential energy to kinetic energy. We notice one thing about the equation for the potential energy P , which is that it is not only directly proportional to h but also is linear in h as well(which is the main reason why a) is correct) which means that if the ice drops by 1 meter the potential energy it will have lost would be ΔPE=mgΔh=-mg, where Δh is the change in its height which is 1 meter here.And according to the principle of conservation of energy this energy must be converted to kinetic energy so the ΔKE=-ΔPE=mg, and this process repeats and for each meter it falls, it picks up the same amount of kinetic energy equaling mg(which is the same as the loss in PE per each meter of fall). So a 2 meter decrease in height will result in an increase in KE of 2mg, a 3 meter decrease in height will result in an increase in KE of 3mg. gain in kinetic energy only depends on the drop in height, which is true irrespective of where the ice might happen to be in its journey close to the top or the bottom. So the drop in height of lets say x at any point in the journey will result in the same increase in KE = ΔKE = mgx. Which proves part a) to be correct.

7 0

3 years ago

Two students race up a flight of steps together. "Student A" reaches the top of the steps 2 seconds ahead of

oksano4ka [1.4K]

Um student a because they were there a few seconds ahead

3 0

3 years ago

A diver leaves the end of a 4.0 m high diving board and strikes the water 1.3s later, 3.0m beyond the end of the board. Consider

shutvik [7]

Answer:

4.0 m/s

Explanation:

The motion of the diver is the motion of a projectile: so we need to find the horizontal and the vertical component of the initial velocity.

Let's consider the horizontal motion first. This motion occurs with constant speed, so the distance covered in a time t is

$d=v_x t$

where here we have

d = 3.0 m is the horizontal distance covered

vx is the horizontal velocity

t = 1.3 s is the duration of the fall

Solving for vx,

$v_x = \frac{d}{t}=\frac{3.0 m}{1.3 s}=2.3 m/s$

Now let's consider the vertical motion: this is an accelerated motion with constant acceleration g=9.8 m/s^2 towards the ground. The vertical position at time t is given by

$y(t) = h + v_y t - \frac{1}{2}gt^2$

where

h = 4.0 m is the initial height

vy is the initial vertical velocity

We know that at t = 1.3 s, the vertical position is zero: y = 0. Substituting these numbers, we can find vy

$0=h+v_y t - \frac{1}{2}gt^2\\v_y = \frac{0.5gt^2-h}{t}=\frac{0.5(9.8 m/s^2)(1.3 s)^2-4.0 m}{1.3 s}=3.3 m/s$

So now we can find the magnitude of the initial velocity:

$v=\sqrt{v_x^2+v_y^2}=\sqrt{(2.3 m/s)^2+(3.3 m/s)^2}=4.0 m/s$

4 0

4 years ago

All stars in a stellar cluster have roughly the same:___.

3241004551 [841]

All stars in a stellar cluster have roughly the same distance.

<h3>What coloration are celebrity clusters?</h3>

Open clusters have a tendency to be blue in color. They frequently include glowing gas and dust. The stars in an open cluster are young stars that all formed from the equal nebula. These warm blue stars are in an open cluster known as the Jewel Bo

<h3>Are stars in the identical cluster?</h3>

Though stellar associations are grouped in with megastar clusters, they're pretty a bit different. "Stellar associations are companies of tens to hundreds of stars that have similar a while and metallicities, and are moving in roughly the equal direction within the galaxy, but are no longer gravitationally bound," Geller said.

Learn more about star cluster here:

<h3>brainly.com/question/20326847</h3><h3 /><h3>#SPJ4</h3>

4 0

1 year ago

How is one kg mass defined in SI system​

How is one kg mass defined in SI system