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3 years ago

What is one standard kilogramun si system

2 answers:

4 0

The kilogram (kg) is defined by taking the fixed numerical value of the Planck constant h to be 6.62607015 ×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.

Phoenix [80]3 years ago

3 0

Answer:

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The image shows a model of the gravitational field around Earth. Which best describes the model?

GuDViN [60]

Answer: The model is described by :

The strength of the field increases as you get closer to Earth, as shown by the smaller spaces between the circles.

Explanation :

According to universal gravitational law, the force acting in the universe between two objects is given by :

$F=G\dfrac{m_1m_2}{r^2}$

It is clear that the gravitational force depends directly on the product of masses and inversely on the square of the distance between them.

The given image shows a model of the gravitational field around Earth. The arrows in the image show the direction of the force. Gravitational field depends on the position of objects.

As we move closer to the earth, the force increases and hence the field increase.

So, the correct option is (D) " The strength of the field increases as you get closer to Earth, as shown by the smaller spaces between the circles ".

3 0

3 years ago

Read 2 more answers

The energy of the electron in Hydrogen atom can be shown to be given by En = -13.6/n^2 eV, where n represents the principal quan

Tpy6a [65]

Answer:

This represents radiation in ultra-violet region .

Explanation:

Energy of the orbit where n = 3 is given as follows

$E_3 =- \frac{13.6 }{3^2}$

$E_3 =- \frac{13.6 }{9}$ = -1.511 eV

Energy of the orbit where n = 1 is given as follows

$E_1 =- \frac{13.6 }{1^2}$

$E_1 =- \frac{13.6 }{1}$ = 13.6 eV

Difference of [tex]E_3 and [tex]E_1 = - 1.511+ 13.6

= 12.089 eV.

The wavelength of light having this energy in nm is given by the expression as follows

Wavelength in nm = 1244 / energy in eV

= 1244 / 12.089

= 102.90 nm

This represents radiation in ultra-violet region .

8 0

3 years ago

A sled is moving down a steep hill. The mass of the sled is 50 kg and the net force acting on it is 20 N. What must be done to f

amid [387]

You need to first measure the angle of descent, i.e. the angle the hill makes with the ground. Then identify the forces acting on the sled, split them up into horizontal and vertical components, or into components that are parallel and perpendicular to the hill, and use Newton's second law to determine the components of the sled's acceleration vector.

There are at least 2 forces acting on the sled:

• its weight, pointing downward with magnitude W = m g

• the normal force, pointing perpendicular to the hill and away from the ground with mag. N

The question doesn't specify, but there might also be friction to consider, indicated in the attachment by the vector F pointing parallel to the slope of the hill and opposing the direction of the sled's motion with mag. F.

Splitting up the forces into parallel/perpendicular components is less work. By Newton's second law, the net force (denoted with ∑ or "sigma" here) in a particular direction is equal to the mass of the sled times its acceleration in that direction:

∑ (//) = W (//) = m a (//)

∑ (⟂) = W (⟂) + N = m a (⟂)

where, for instance, W (//) denotes the component of the sled's weight in the direction parallel to the hill, while a (⟂) denotes the component of the sled's acceleration perpendicular to the hill. If there is friction, you need to add -F to the first equation.

If the hill makes an angle of θ with flat ground, then W makes the same angle with the hill so that

W (//) = -m g sin(θ)

W (⟂) = -m g cos(θ)

So we have

-m g sin(θ) = m a (//) → a (//) = -g sin(θ)

-m g cos(θ) + N = m a (⟂) → a (⟂) = 0

where the last equality follows from the fact that the normal force exactly opposes the perpendicular component of the weight. This is because the sled is moving along the slope of the hill, and not into the air or into the ground.

Then the acceleration vector is

a = a (//)

with magnitude

||a|| = a = g sin(θ).

6 0

3 years ago

3. Tyrone wants to determine how fast a bowling ball travels when it is bowled. He uses a stopwatch to

SVEN [57.7K]

Meters would be the best way to record the length

7 0

3 years ago

All matter has electrical and magnetic properties because the atoms that make up matter are held together by electromagnetic for

leva [86]

Answer:

Charge

Explanation:

Charge is a fundamental property of all matter. All matter has electrical and magnetic properties because the atoms that make up matter are held together by electromagnetic forces.

These charges are usually positive and negative charges. When these charges which make up an atom (positive and negative) are equal, the atom is said to be electrically neutral. When positive charge is greater than negative charge, the atom is said to positively charged. Also, if the number of negative charges are more in an atom, the atom is said to be negatively charged.

7 0

3 years ago

What is one standard kilogramun si system​

What is one standard kilogramun si system