1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
diamong [38]
2 years ago
11

Your cousin Jannik skis down a blue square ski slope, with an initial speed of 3.6 m/s. He travels 15 m down the mountain side b

efore coming to a flat landing. Jannik estimates the blue skislope has a 40 percent grade, or 18◦ incline above the horizontal and that he and his skis have a total mass of 58.0 kg. Suppose that the hillside is not frictionless, so that Jannik’s speed at the bottom of the slope is 7.8 m/s. What is the energy lost due to friction when Jannik reaches the flat landing? Justify your response.
Physics
1 answer:
fenix001 [56]2 years ago
8 0

Answer: The loss of energy due to friction is equal to 1,253 J.

Explanation:

The problem tells us that the skier has an initial speed of 3.6 m/s, which means that his initial kinetic energy is as follows:

K₁ = 1/2 m v₁² = 1/2 . 58.0 Kg. (3.6)² (m/s)² =  376 J

After coming to a  flat landing, his final speed is 7.8 m/s, so the final kinetic energy is as follows:

K₂ = 1/2 m v₂² = 1/2. 58.0 Kg. (7.8)² (m/s)² = 1,764 J

Now, when skying down the slope the increase in kinetic energy only can come from another type of energy, in this case, gravitational potential energy.

If we take the ground flat level as a Zero reference, the initial gravitational potential energy, can be written as follows, by definition:

U₁ = m.g. h (1)

Now, we don't know the value of the height h, but we know that the incline has a 18º angle above the horizontal, and that the distance travelled along the incline is 15 m.

By definition, the sinus of an angle, is equal to the proportion between the height and the hypotenuse , so we can write the following equation:

sin 18º = h / 15 m ⇒ h = 15 m. sin 18º = 4.6 m

Replacing in (1), we get:

U₁ = 58.0 Kg. 9.8 m/s². 4.6 m = 2,641 J

So, we can get the total initial mechanical energy, as follows:

E₁ = K₁ + U₁ = 376 J + 2,641 J = 3,017 J

After arriving to the flat zone, all potential energy has become in kinetic energy, even though not completely, due to the effect of friction.

This remaining kinetic energy can be written as follows:

E₂ = K₂ = 1,764 J

The difference E₂-E₁, is the loss of energy due to friction forces acting during the travel along the 15 m path, and is as follows:

ΔE= E₂ - E₁ = 1,764 J - 3,017 J = -1,253 J

You might be interested in
Red giants are smaller than main sequence stars, which are smaller than white dwarfs.
avanturin [10]
<span> False. A Red Giant evolves from a main sequence star after it commences Helium fusion and undergoes a great expansion; in the case of our Sun it would expand to encompass Earth's orbit. Thus, it would have approximately the same mass (a small amount being expelled in the helium flash), and vastly greater volume, equating to vastly lower density.

You're welcome :)
</span>
8 0
3 years ago
Who are people that you can go to for help name three?
joja [24]

Answer:

parent

teacher

peer

Explanation:

6 0
3 years ago
Read 2 more answers
A rifle fires a 2.90 x 10-2-kg pellet straight upward, because the pellet rests on a compressed spring that is released when the
iren2701 [21]

Answer: 586.60N/m

Explanation:

In this scenario, the elastic potential energy of the spring is converted into potential energy.

0.5*K*x^2 = mgh

Thus K = 2mgh/x^2

=(2*2.90*10^-2*9.8*7.23)/(8.37*10^-2)^2

=586.599

Therefore K = 586.60N/m

7 0
3 years ago
Read 2 more answers
A woman lifts her 100-newton child up one meter and carries her for a distance of 50 meters to the child's bedroom. How much wor
tankabanditka [31]
100 J

Please mark me brainliest it would be greatly appreciated haha
5 0
3 years ago
Read 2 more answers
A particle with positive charge q = 9.61 10-19 C moves with a velocity v = (5î + 4ĵ − k) m/s through a region where both a unifo
user100 [1]

Answer:

\vec{F}=(1.537*10^{-17}\hat{i}-9.61*10^{-19}\hat{j}-2.883*10^{-18}\hat{k})N

Explanation:

The total force on the particle is given by

\vec{F}=q\vec{v}\ X\ \vec{B}+q\vec{E}

Then, by replacing we have:

q\vec{v}\ X \vec{B}=q[7\hat{k}-9\hat{j}-\hat{k}]\\\\q\vec{E}=q[5\hat{i}-\hat{j}-2\hat{k}]\\\\\vec{F}=(9.61*10^{-19}C)[(7+9)\hat{i}+(-9-1)\hat{j}+(-1-2)\hat{k}]\\\\\vec{F}=(1.537*10^{-17}\hat{i}-9.61*10^{-19}\hat{j}-2.883*10^{-18}\hat{k})N

where the cross product can be made with the determinant method.

Hope this helps!!

3 0
3 years ago
Read 2 more answers
Other questions:
  • Tiana jogs 1.5 km along a straight path and then turns and jogs 2.4 km in the opposite direction. She then turns back and jogs 0
    11·1 answer
  • Anybody wanna help? (Picture Included?)
    5·2 answers
  • If you are traveling in a primary channel and you encounter a red and green marker (with the green band on top) when proceeding
    9·1 answer
  • A ball is thrown vertically upward from the top of a building 80 feet tall with an initial velocity of 64 feet per second. The d
    6·2 answers
  • A T-shirt is launched at an angle of 30° with an initial velocity of 25 m/s how long does it take to reach the peak? How long is
    8·1 answer
  • Answer in detail? Describe an activity that gives an understanding of ‘Electrostatic force’.
    5·1 answer
  • Can you guys help me with this guestion?
    10·1 answer
  • A dog accelerates at 1.50 m/s2 to reach a velocity of 13.5 m/s while covering a distance of 49.3 m. What was his initial velocit
    9·1 answer
  • Please help if you do I will give you 50 points and brainliest. I'll give you 50 points by posting another question just to make
    11·1 answer
  • What was the first and largest asteroid to be identified?.
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!