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
victus00 [196]
3 years ago
7

A metal block of mass 235 g rests at a point 2.8 m from the center of a horizontal rotating wooden platform. The coefficient of

static friction between the block and the platform is 0.437. The platform initially rotates very slowly but the rotation rate is gradually increasing. The acceleration of gravity is 9.8 m/s 2 . At what minimum angular velocity of the platform would the block slide away? Answer in units of rad/s.
Physics
1 answer:
Nuetrik [128]3 years ago
5 0

Answer:

ω=1.23 rad/sec

Explanation:

The block will start sliding when the centrifugal force exceeds the force of friction

We have Force of friction and centrifugal force are as under

F_{f}=\mu mg...........(i)\\\\F_{c.f}=m\omega ^{2}r................(ii)

Thus equating the 2 forces to get the minimum angular velocity we have

\fr\mu mg= m\omega^{2}r\\\\\therefore \omega =(\frac{\mu g}{r})^{1/2}

Applying values we get

ω=1.23 rad/sec

You might be interested in
Two blocks of masses m and M are connected by a string and pass over a frictionless pulley. Mass m hangs vertically, and mass M
horsena [70]

Answer:

sin\theta - \mu_k cos\theta = \frac{m}{M}

sin\theta - \mu_k cos\theta = 1

Explanation:

Force of friction on M mass so that it will move down the inclined plane is given as

F_f = \mu Mgcos\theta

now if it is moving down the inclined plane at constant speed

so we will have

Mgsin\theta - T - \mu mgcos\theta = 0

on other side the mass "m" will go up at constant speed

so we have

T - mg = 0

so we have

Mgsin\theta = \mu Mgcos\theta + mg

so we have

sin\theta - \mu_k cos\theta = \frac{m}{M}

for special case when m = M

then we have

sin\theta - \mu_k cos\theta = 1

5 0
3 years ago
A hot-air balloon has a volume of 440 × 10^3 ^3. Calculate the buoyant force that the surrounding cold air exerts on the balloon
siniylev [52]

Answer:

Explanation:

Given that,

The volume of the balloon is

V = 440 × 10³ m³

Buoyant force F?

Given the density of the surrounding to be 2.58 kg/m³

ρ = 2.58 kg/m³

The buoyant force is the weight of water displaced and it is calculated using

F_b = ρVg

Where

F_b is buoyant force

ρ is density

V is the volume of the liquid displace.

g is the acceleration due to gravity

Then,

F_b = ρVg

F_b = 2.58 × 440 × 10³ × 9.81

F_b = 1.1 × 10^7 N

3 0
3 years ago
Describe how the mass, luminosity, surface temperature, and radius of main-sequence stars change in value going from the “bottom
Sladkaya [172]

Answer:

1. Least massive stars are the coolest and least luminous, lower right of main sequence, on HR diagram.  

2. Most massive are the hottest and most luminous, upper left of main sequence on Hr Diagram.  

3. The radius of stars are related to their sprectral type. having the O being the hottest upper left and M being the coolest bottom right.

4 0
3 years ago
In the 1920s what did Edmund hubble notice about the galaxies
zlopas [31]
Hubble noticed that the galaxies were moving away from us, which meant the universe was expanding.

This is why constellations change over time. In some years, the Big Dipper won't actually look like a dipper anymore.
5 0
3 years ago
Define an element and give 5 examples of elements that are important to life .
fenix001 [56]

Answer:

A pure substance consisting only of atoms with the same number of protons in their nuclei-these appear on the periodic table

Oxygen

Hydrogen

Carbon

Sulfur

Phosphate

Nitrogen

Magnesium

Calcium

Potassium

Chlorine

(I know that these are more examples than needed, but you can use any)

8 0
3 years ago
Other questions:
  • What relation does the boiling point of an amine have to a similar hydrocarbon?
    14·2 answers
  • 1. in which lover of Earth are temperature and<br> pressure greatest?<br> 1-A<br> B <br> C <br> D
    11·1 answer
  • Which property describes the temperature at which a liquid changes to a gas?
    5·1 answer
  • Which statement best summarizes the central idea of "Applications of Newton's Law
    10·2 answers
  • A wave has a period of 4 seconds. What is its frequency?
    15·1 answer
  • Air flows through a converging-diverging nozzle/diffuser. A normal shock stands in the diverging section of the nozzle. Assuming
    5·1 answer
  • A rifle is aimed horizontally at a target 50.0 m away. The bullet hits the target 2.90 cm below the aim point. . . Whats the bul
    14·1 answer
  • Two ice skaters push off against one another starting from a stationary position. The 54.1-kg skater acquires a speed of 0.375 m
    7·1 answer
  • Difference between the fertility rate and mortality rate of developed and least development countries
    13·1 answer
  • Which would deliver a greater change in momentum to an opponent’s body - a dodgeball that traveled at 10m/s and rebounded with a
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!