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
makvit [3.9K]
2 years ago
10

A 73-kg Norwegian olympian ski champion is going down a hill sloped at 39 ◦ . The coefficient of kinetic friction between the sk

is and the snow is 0.15. a. How fast is the skier going 5.0 s after starting from rest? b. After the Norwegian skier has been moving for 5.0 s, the friction of the snow suddenly increased making the net force on the skier zero. What is the new coefficient of friction? c. How fast would the skier now be going after skiing for 5.0s?
Physics
1 answer:
bazaltina [42]2 years ago
5 0

Answer:

Explanation:

net force on the skier = mg sin 39 - μ mg cos39

mg ( sin39 - μ cos39 )

= 73 x 9.8 ( .629 - .116)

= 367 N

impulse = net force x time = change in momentum .

= 367 x 5 = 1835 kg m /s

velocity of the skier after 5 s = 1835 / 73

= 25.13 m /s

b )

net force becomes zero

mg ( sin39 - μ cos39 ) = 0

μ = tan39

= .81

c )

net force becomes zero , so he will continue to go ahead with constant speed of 25.13 m /s

so he will have speed of 25.13 m /s after 5 s .

You might be interested in
the distance between any two bodies is 10 M and the gravitational force between them is 3.2×10-⁹m. if the mass of one object is
cluponka [151]

Answer:

0.8 x 10^-9 kg

Explanation:

Given,

Distance ( R ) = 10 m

Force ( F ) = 3.2 x 10^-9 N

Mass ( m1 ) = 40 kg

To find : Mass ( m2 ) = ?

Formula : -

F = m1.m2 / R^2

m2 = FR^2 / m1

= 3.2 x 10^-9 x 10 / 40

= 3.2 x 10^-9 / 4

= ( 3.2 / 4 ) x 10^-9

m2 = 0.8 x 10^-9 kg

3 0
3 years ago
A stunt man jumps from the top of a building and lands 10 meters below his initial height. In case A, the stunt man lands on a s
krek1111 [17]

Answer:

Explanation:

The stunt will likely sustain serious injury in case of concrete blocks because the average force acting on the person will be more because concrete blocks do not squeeze to provide more time for the force to act on the body instead it acts for a small amount of interval.

Impulse=F_{avg}\times \Delta T

As impulse is constant so time requires to act force on the body is more as compared to concrete block and thus average force in mattress case is less.  

8 0
3 years ago
An astronaut goes to Mars to do some experiments. Explain why her mass stays the same but her weight changes.
Snowcat [4.5K]
Because mass does not change from place to place but weight does change from place to place... why? because weight is the amount of gravitational force on an object and mass is the amount of matter in an object. mars has less gravitational force so an object will weigh less than it really weighs there
6 0
2 years ago
A horizontal beam of light of intensity 25 W/m2 is sent through two polarizing sheets. The polarizing direction of the first mak
Zina [86]

Answer:

option (B)

Explanation:

Intensity of unpolarised light, I = 25 W/m^2

When it passes from first polarisr, the intensity of light becomes

I'=\frac{I_{0}}{2}=\frac{25}{2}=12.5 W/m^{2}

Let the intensity of light as it passes from second polariser is I''.

According to the law of Malus

I'' = I' Cos^{2}\theta

Where, θ be the angle between the axis first polariser and the second polariser.

I'' = 12.5\times Cos^{2}15

I'' = 11.66 W/m^2

I'' = 11.7 W/m^2

7 0
3 years ago
Which factor contributes the most to the process of water erosion?
asambeis [7]
The answer is b or d u chooose i don’t know which one
6 0
3 years ago
Read 2 more answers
Other questions:
  • Use the periodic table to identify the number of core electrons and the number of valence electrons in each case below. Potassiu
    12·2 answers
  • What are two different ways to understand time? Explain and give example?
    14·1 answer
  • When aluminum-27 is bombarded with a neutron, a gamma ray is emitted. what radioactive isotope is produced?
    10·2 answers
  • In a transverse wave, the motion of the disturbance is in what direction relative to the wave motion? opposite parallel perpendi
    11·2 answers
  • a person Travels along a straight road for half the distance with velocity V1 and the remaining half the distance with velocity
    7·1 answer
  • Correct displacement 4km south,2 km north, 5km south, and 5 km north
    10·1 answer
  • Scientists might live too far away to meet face to face. What are the three other ways they can share data and discuss evidence?
    9·2 answers
  • Josh and jake are both helping to build a brick wall which is 6 meters in height. They each lay 250 bricks, but josh finishes th
    5·1 answer
  • Assume a current of 1 ampere enters a parallel circuit at Point A. This 1 ampere of current will ________________ between Resist
    15·1 answer
  • The size of a wave is NOT affected by the
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!