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3 years ago

A skier is skiing down a slope on the mountain.

Physics

1 answer:

uysha [10]3 years ago

4 0

The mechanical energy isn't conserved. Some energy is lost to friction.

Option A.

<h3><u>Explanation:</u></h3>

The mechanical energy is defined as the energy of a body which it achieves by virtue of its position and velocity. The mechanical energy are of two types - potential energy and kinetic energy. The potential energy is the energy of the body which it achieves by means of its relative position and is directly proportional to the height of the body from its relative plane. Whereas the kinetic energy of the body is achieved by virtue of its velocity and is directly proportional to the square of velocity of the body.

As the mountaineer is skiing down the slope of a mountain, the potential energy of the person is gradually changing into his kinetic energy. Had it been in an ideal situation, the potential energy lost would have been just equal to the kinetic energy gained by the person. But there's friction which opposes the speed of the body and reduces the velocity. Thus the kinetic energy will be lost to some extent and the energy won't be conserved.

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Help please!

kipiarov [429]

<h2>Answer: Diamond</h2>

Explanation:

This described situation is known as Refraction, a phenomenon in which the light bends or changes it direction when passing through a medium with a index of refraction different from the other medium.

In this context, the index of refraction is a number that describes how fast light propagates through a medium or material.

According to Snell’s Law:

$n_{1}sin(\theta_{1})=n_{2}sin(\theta_{2})$ (1)

Where:

$n_{1}=1$ is the first medium index of refraction (air)

$n_{2}$ is the second medium index of refraction (the value we want to know)

$\theta_{1}=27\°$ is the angle of the incident ray

$\theta_{2}=11\°$ is the angle of the refracted ray

Now, let's find $n_{2}$ from (1):

$n_{2}=n_{1}\frac{sin(\theta_{1}}{sin(\theta_{2}}$ (2)

Substituting the known values:

$n_{2}=(1)\frac{sin(27\°)}{sin(11\°)}}$

Finally:

$n_{2}=2.379\approx 2.4$

If we compare this result with the given table, the index of refraction value that is close to this number is diamond's index of refraction.

Therefore, the correct option is A: the material is diamond.

3 0

3 years ago

A proton traveling due west in a region that contains only a magnetic field experiences a vertically upward force (away from the

Vikki [24]

South

Explanation:

The magnetic force F on a point charge moving with a velocity v in the presence of a magnetic field B is given by

$\vec{\textbf{F}} = q\vec{\textbf{v}}\textbf{×}\vec{\textbf{B}}$

and according to the right-hand rule, an upward magnetic force on a proton moving westward is only possible if the magnetic field is directed southward.

3 0

3 years ago

Which is the correct interpretation of the formula mgf2? the lattice contains 1 magnesium atom for every 2 fluorine atoms. the l

mixer [17]

Answer: the lattice contains 1 magnesium ion for every 2 fluoride ions.

$MgF_2$ is an ionic compound. It contains positive ions of Magnesium and and negative ions of Fluorine. To balance the +2 positive charge of one magnesium ion, two (-1) negatively charged Fluorine ions are present. Hence, The correct interpretation of $MgF_2$ is that the lattice contains 1 Magnesium ion for every 2 Fluoride ions.

7 0

3 years ago

Two equal positive charges are held in place at a fixed distance. If you put a third positive charge midway between these two ch

eimsori [14]

Answer:

False

Explanation:

8 0

3 years ago

A 1500 kg elevator, suspended by a single cable with tension 16.0 kN, is measured to be moving upward at 1.2 m/s. Air resistance

kirill115 [55]

Tension in the Cable is 0.87 m/s6^2, Elevator's speed after it has moved 10m is 1.6*10^5 N, Work done by gravity is 1.47 * 10^3 N, Elevator Kinetic Energy is 13897.5J and Elevator Speed after rising to 10m is 4.312 m/s.

Tension is a pulling force that operates in one dimension along the cables' axes in the opposite direction from the direction of the applied force. The combined weight of the elevator box and the passenger riding inside it, in the case of an elevator, provides the pulling force in the cables is called Tension.

A moving object or particle's kinetic energy, which depends on both mass and speed, is one of its characteristics. The type of motion can be vibration, translation, rotation around an axis, or any combination of these. Kinetic energy is a type of energy that an item or particle possesses as a result of motion.

We know that,

Tension in the Cable

T = m(g+a) = g+a = T/m = 16 * 103 / 1500 = 10.67 m/s2

a = 10.67 - 9.8 = 0.87 m/s6^2

Elevator's speed after it has moved 10m.

U^2 = u^2 +2as

= 1.22 +2*0.87*10

=1.6*10^5 N

Work done by gravity = mg * 10 = 14700 * 10 = 1.47 * 10^3 N

Elevator Kinetic Energy = 1/2 mv^2 = 1/2*1500*18.53 = 13897.5J

Elevator Speed after rising to 10m ,

U^2 = u^2 +2as = 1.2 +2*0.87*10 = 18.6

U =(18.6)^1/2=4.312 m/s

Learn more about Kinetic Energy here

brainly.com/question/26472013

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6 0

1 year ago