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
avanturin [10]
3 years ago
7

A 110 kg ice hockey player skates at 3.0 m/s toward a railing at the edge of the ice and then stops himself by grasping the rail

ing with his outstretched arms. During the stopping process, his center of mass moves 30 cm toward the railing. (a) What is the change in the kinetic energy of his center of mass during this process? (b) What average force must he exert on the railing?
Physics
2 answers:
tresset_1 [31]3 years ago
8 0

Answer:

(a). The change in the kinetic energy of his center of mass during this process is -495 J.

(b). The average force is 1650 N.

Explanation:

Given that,

Mass = 110 kg

Speed = 3.0 m/s

Distance = 30 cm

(a). We need to calculate the change in the kinetic energy of his center of mass during this process

Using formula of kinetic energy

\Delta K.E=K.E_{2}-K.E_{1}

\Delta K.E=\dfrac{1}{2}mv_{f}^2-\dfrac{1}{2}mv_{i}^2

Put the value into the formula

\Delta K.E=\dfrac{1}{2}\times110\times0^2-\dfrac{1}{2}\times110\times(3.0)^2

\Delta K.E=-495\ J

(b). We need to calculate the average force must he exert on the railing

Using work energy theorem

W=\Delta K.E

Fd=\Delta K.E

F=\dfrac{\Delta K.E}{d}

Put the value into the formula

F=\dfrac{-495}{30\times10^{-2}}

F=-1650\ N

The average force is 1650 N.

Hence, (a). The change in the kinetic energy of his center of mass during this process is -495 J.

(b). The average force is 1650 N.

disa [49]3 years ago
7 0

Answer

given,

mass of ice hockey player = 110 Kg

initial speed of the skate = 3 m/s

final speed of the skate = 0 m/s

distance of the center of mass, m = 30 cm = 0.3 m

a) Change in kinetic energy

    \Delta KE = \dfrac{1}{2}mv_f^2 - \dfrac{1}{2}mv_i^2

    \Delta KE = \dfrac{1}{2}m(0)^2 - \dfrac{1}{2}\times 110 \times 3^2

    \Delta KE = - 495\ J

b) Average force must he exerted on the railing

     using work energy theorem

      W = Δ KE

      F .d  = -495

      F x 0.3  = -495

      F = -1650 N

the average force exerted on the railing is equal to 1650 N.

You might be interested in
Convert to the fractional equivalent and reduce 21.12
nignag [31]

The decimal point is placed after two digits starting from the end. For each decimal place, we can write the number divided by 100.

21.12 can be written as \frac{2112}{100}.

Divide the numerator and denominator by 2:

\frac{2112}{100}= \frac{156}{50}

The numerator and denominator can be divided by 2 again:

\frac{78}{25}

There is no other common factor between numerator and denominator other than 1. Hence, it is the reduced form.




3 0
3 years ago
Read 2 more answers
How would you determine the volume of an irregular shaped object.
Archy [21]
You can use the displacement method or the eureka can so basically in the displacement can what you have to do is to put some water into a measuring cylinder and measure its volume before adding the irregular shaped object and then measuring the level of water which had been displaced and then eureka can you can check online
7 0
4 years ago
Hey, I need help can someone help me out, please?
yan [13]

Explanation:

6) newton

7) f =ma = 15*15 = 225N

8) a= 100/20 = 5ms^-2

6 0
3 years ago
Read 2 more answers
If 270 watts of power is used in 42 seconds, how much work was done<br>​
navik [9.2K]

Answer: W = 11340J

Explanation:

Hey there! I will give the following steps, if you have any questions feel free to ask me in the comments below.

So this is the Formula: Power = Work / Time.

<u>Step 1:</u><em><u> Find the Formula</u></em>

P = W / T

<em><u> </u></em>

<u>Step 2: </u><u><em>Make W the subject of the equation.</em></u>

W = PT

<u>Step 3:</u><u> </u><u><em>Given.</em></u>

P = 270 Watts, T = 42 seconds

<u>Step 4:</u><u><em> Substitute these values into equation 2 .</em></u>

W = 270(42)

<u>Step 5:</u><u> </u><u><em>Simplify.</em></u>

W = 11340J

The amount of work done was 11340.

~I hope I helped you! :)~

4 0
3 years ago
Why does the spectroscopic parallax method only work for main sequence stars?.
Brums [2.3K]

Answer:

Only main sequence stars have a well-defined relationship between spectral type and luminosity.

Explanation:

Low-mass stars have much longer lifetimes than high-mass stars.

5 0
2 years ago
Other questions:
  • The flow of cold dense air under the influence of gravity is called a _________ .
    14·1 answer
  • _________ are exchanged or shared during the formation of a chemical bond.
    12·2 answers
  • What upward gravitational force does a 5600kg elephant exert on the earth?
    12·2 answers
  • Monochromatic light of variable wavelength is incident normally on a thin sheet of plastic film in air. The reflected light is a
    10·1 answer
  • In a carnival booth, you can win a stuffed giraffe if you toss a quarter into a small dish. the dish is on a shelf above the poi
    11·1 answer
  • according to the theory developed by Charles darwin what process causes organisms to develop traita that help them adapt to chan
    14·2 answers
  • Assume an axon has an internal diameter of 1μm and a myelin sheath 1μm thick. The internal specific resistance is 100 Ω cm. For
    14·1 answer
  • What happens during an equinox?
    10·1 answer
  • What is the abbreviation for the SI unit for electric potential?<br> V<br> J<br> C<br> U
    13·1 answer
  • a small asteroid of mass 125 kg is orbiting a planet that has a mass of 3.52x 10^13 what is the radial distance between the aste
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!