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
anyanavicka [17]
3 years ago
6

A man stands on a platform that is rotating at 3.8 rpm; his arms are outstretched and he holds a brick in each hand. The rotatio

nal inertia of the system consisting of the man, bricks, and platform about the central axis of the platform is 4.65 kg-m². By moving the bricks the man decreases the rotational inertia of the system to 3.4 kg-m².
(a) what is the resulting angular speed of the platform and
(b) what is the ratio of the new kinetic energy of the system to the original kinetic energy?

Physics
2 answers:
Ierofanga [76]3 years ago
8 0

Answer:

a) 5.197rev/s

b) Kf/Ki =2.28

Explanation:

a) Angular momentum of the system L = Iw

ButLi=Lf

Kiwi =Ifwf

wf = (Ii/If)will = (4.65/3.4)×3.8=5.197rev/s

b)Kinetic energy KE= 0.5Iw^2

Ki = 0.5Iiwi^2

Kf=0.5Ifwf^2

Kf/Ki = Ifwf/Iiwi

Kf/Ki = (4.65/3.4))(5.197/3.8)

Kf/Ki = 1.22(1.368)^2

Kf/Ki = 2.28

kiruha [24]3 years ago
7 0

Answer:

A. 5.2 rpm.

B. Kf/Ki = 1.37.

Explanation:

Below is an attachment containing the solution.

You might be interested in
Which characteristics of an area could best identify the type of biome it is
jeka94

Answer: average annual rainfall, average annual temperatures, types of plants and animals native to the area

Explanation: the best way you can identify a biome is by telling which animal or species are native to the certain area

6 0
2 years ago
A pear hangs in a tree at a height of 1.8 m. The pear has a mass of 0.2 kg. The pear falls out of the tree and lands on the grou
TiliK225 [7]

a) PE=mgh=0.2*9.8*1.2=2.352 J

b) KE=PE=2.352 J

c) v=\sqrt{\frac{2KE}{m}}=4.85 m/s

6 0
3 years ago
What’s being done to the brake fluid in the above photo?
ch4aika [34]

Answer:

D. Checking to see if the brake fluid is contaminated

Explanation:

5 0
3 years ago
A planet orbits a star, in a year of length 3.37 x 107 s, in a nearly circular orbit of radius 1.04 x 1011 m. With respect to th
PIT_PIT [208]

Answer

Given,

Time period of star,T = 3.37 x 10⁷ s

Radius of circular orbit,R = 1.04 x 10¹¹ m

a) Angular speed of the planet

   \omega = \dfrac{2\pi}{T}=\dfrac{2\pi}{3.37\times 10^{7}}

   \omega = 1.864\times 10^{-7}\ rad/s

b) tangential speed

   v = r \omega = 1.04\times 10^{11}\times 1.864 \times 10^{-7}

       v = 1.94 x 10⁴ m/s

c) centripetal acceleration magnitude

      a = \dfrac{v^2}{r}= \dfrac{(1.94\times 10^4)^2}{1.04\times 10^{11}}

          a = 3.62 x 10⁻³ m/s²

8 0
3 years ago
What inferences can you make about the melting points of the different substances and the motion of their particles, based on th
miv72 [106K]
Here’s the answer now hand over the brainilyiest

7 0
2 years ago
Other questions:
  • What is the relationship between air pressure and air temperature?
    9·1 answer
  • Suzie riding her bike is able to get her bike to 20m/s in just 5 seconds. What is her acceleration?
    5·1 answer
  • The table below shows the difference between the average temperatures in April and October in four locations.
    12·1 answer
  • An object that is dropped straight down from a height of 100 m has a vertical change in position that is less than that of an id
    7·1 answer
  • In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the sys
    14·1 answer
  • What would be the volume of a liquid that has a density of 1.2 g/mL and a mass of 24 grams
    15·1 answer
  • The value of acceleration due to gravity (g) on Pluto is about . 0.61 meters/second2. How much will an object that weighs 250 ne
    11·1 answer
  • A small turbo-prop commuter airplane, starting from rest on a Lansing airport runway, accelerates for 22.5s before taking off. I
    6·1 answer
  • What is the answer I put down 8/ms but my teacher said it was wrong
    12·1 answer
  • A huge block of stone has a mass of 650kg and gains 70000j of gpe. how high has it been raised? (g = 10m/s2 )
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!