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
BaLLatris [955]
3 years ago
12

n a downhill ski race, surprisingly, little advantage is gained by getting a running start. (This is because the initial kinetic

energy is small compared with the gain in gravitational potential energy on even small hills.) To demonstrate this, find the final speed and the time taken for a skier who skies 70.0 m along a 30â slope neglecting friction: (a) Starting from rest. (b) Starting with an initial speed of 2.50 m/s. (c) Does the answer surprise you? Discuss why it is still advantageous to get a running start in very competitive events.
Physics
1 answer:
Annette [7]3 years ago
7 0

Answer:

Explanation:

a ) starting from rest , so u = o and initial kinetic energy = 0 .

Let mass of the skier = m

Kinetic energy gained = potential energy lost

= mgh = mg l sinθ

= m x 9.8 x 70 x sin 30

= 343 m

Total kinetic energy at the base = 343 m  + 0 = 343 m .

b )

In this case initial kinetic energy = 1/2 m v²

= .5 x m x 2.5²

= 3.125 m

Total kinetic energy at the base

= 3.125 m  + 343 m

= 346.125 m

c ) It is not surprising as energy gained due to gravitational force by the earth is enormous . So component of energy gained due to gravitational force far exceeds the initial kinetic energy . Still in a competitive event , the fractional initial kinetic energy may be the deciding factor .

You might be interested in
An _________ is a light ray moving toward a boundary.
Sveta_85 [38]

When A Light Ray Hits A Boundary,,,,, it is called refraction.

6 0
3 years ago
A 25.0 kg pickle is accelerated from rest through a distance of 6.0m in 4.0s across a level floor . If the friction force betwee
SIZIF [17.4K]
Add the KE increase and the work done against friction.

The final velocity is twice the average, or 3.0 m/s
The final KE is (1/2)*25*3^2 = 112.5 J

The friction work done is 6*3.8 = 22.8 J 
 hope this is correct
8 0
3 years ago
PLEASE HELP ME !!!
Bogdan [553]

Because the temperature causes it to go the physical change like if water is froze the temperate just caused it to go through another state of matter another example as if the ice got melted you would need high temperature to cause this change physically. Let me know if I help or if their is anything I can change for you to understand better

4 0
3 years ago
Some people believe that the Moon’s phases are caused by Earth’s shadows on the Moon. Is this true?
emmasim [6.3K]
No thats false. If your trying to say is true that people BELIEVED that then yes its true people believed it but if your talking about that question then its false
5 0
3 years ago
You are driving to the grocery store at 18 m/s. You are 120 m from an intersection when the traffic light turns red. Assume that
andrew-mc [135]

Answer:

11.64225 m

Explanation:A = 45 m/s – 15m/s / 6s  

A = 5m/s^2

8 0
3 years ago
Other questions:
  • A capacitor is made from two hollow, coaxial, iron cylinders, one inside the other. The inner cylinder is negatively charged and
    10·1 answer
  • Divergent boundaries are also called
    6·2 answers
  • The measure of one of the small angles of a right triangle is 45 less than twice the measure of the other small angle. Find the
    14·1 answer
  • When the wood block is dropped in the water and settles so that it floats and is no longer bobbing up and down, how do the buoya
    14·1 answer
  • Photosynthesis is an endothermic chemical reaction that forms sugars from carbon dioxide, water, and the sun's energy. Which of
    13·2 answers
  • In a discussion person A is talking 1.2 dB louder than person B, and person C is talking 3.2 dB louder than person A. What is th
    5·1 answer
  • Select all that apply.
    11·2 answers
  • According to the Big Bang theory timeline, all matter and energy was compressed into a very small volume at an extremely high te
    9·1 answer
  • Which of the following is NOT a function of MITOSIS?
    15·1 answer
  • Father, I come to you worn and weary from the hard times I have walked through recently. I come to you seeking your shelter wher
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!