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
ziro4ka [17]
3 years ago
8

A disk rotates freely on a vertical axis with an angular velocity of 30 rpm. An identical disk rotates above it in the same dire

ction about the same axis, but without touching the lower disk, at 20 rpm. The upper disk then drops onto the lower disk. After a short time, because of friction, they rotate together. The final angular velocity of the disks is
A. 50 rpm
B. 40 rpm
C. 25 rpm
D. 20 rpm
E. 10 rpm
Physics
1 answer:
weqwewe [10]3 years ago
8 0

Answer:

c. 25 rpm

Explanation:

The inertia of both disk is the same so

I_1=I_2

I_1*w_{1i}+I_2*w_{2i}=I_1*w_{1f}+I_2*w_{2f}

I*(w_{1i}+w_{2i})=I*(w_{1f}+w_{2f})

w_{1f}=w_{2f}=w_f

w_{1f}+w_{2f}=2w_f

w_f=\frac{w_{1i}+w_{i2}}{2}

w_f=\frac{30rpm+20rpm}{2}

w_f=\frac{50rpm}{2}

w_f=25rpm

You might be interested in
Which area of earth is most similar to the suns convention zone
julsineya [31]
The area of the Earth that is most similar to the Sun's convection zone would be the mantle. The convection zone of the sun is its outermost layer where heat transfer by convection happens which is similar to the Earth's mantle. It would be the crust because it is the outer most layer.
3 0
2 years ago
What layers on earth are considered liquids
Tatiana [17]
<span>Crust. The thin solid outermost layer of Earth. ...Asthenosphere. The lower layer of the crust. ...Lithosphere.Plasticity: is solid but still being able to. flow without being a liquid.The cool, rigid outermost layer of the Earth. ...<span>the solid part of the earth consisting of the crust and outer mantle.</span></span>
6 0
3 years ago
If a vector that is 3cm long represents 30 km/h, what velocity does a 5 cm long vector which is drawn using the same scale repre
FrozenT [24]

Answer:

False knowww yess ofcure

8 0
3 years ago
A capacitor is formed from two concentric spherical conducting shells separated by vacuum. The inner sphere has radius 12.0 cm ,
iren [92.7K]
Energy Density = 1/2 × ε(0) × (V/d)^2

V = 100, d = 0.01, ε(0) = 8.85 x 10^-12
5 0
2 years ago
Find the density of seawater at a depth where the pressure is 500 atm if the density at the surface is 1100 kg/m^3 . Seawater ha
mixer [17]

The density of seawater at a depth where the pressure is 500 atm is 1124kg/m^3

Explanation:

The relationship between bulk modulus and pressure is the following:

B=\rho_0 \frac{\Delta p}{\Delta \rho}

where

B is the bulk modulus

\rho_0 is the density at surface

\Delta p is the variation of pressure

\Delta \rho is the variation of density

In this problem, we have:

B=2.3\cdot 10^9 N/m^2 is the bulk modulus

\rho_0 =1100 kg/m^3

\Delta p = p-p_0 = 500 atm - 1 atm = 499 atm = 5.05\cdot 10^7 Pa is the change in pressure with respect to the surface (the pressure at the surface is 1 atm)

Therefore, we can find the density of the water where the pressure is 500 atm as follows:

\rho = \rho_0 + \Delta \rho = \rho_0+\frac{\rho_0 \Delta p}{B}=\rho_0 (1+\frac{\Delta p}{B})=(1100)(1+\frac{5.05\cdot 10^7}{2.3\cdot 10^9})=1124kg/m^3

Learn more about pressure in a fluid:

brainly.com/question/9805263

#LearnwithBrainly

7 0
3 years ago
Other questions:
  • Under what conditions will the projectile have the greatest velocity when it hits the ground?
    9·1 answer
  • Newton said that something was needed to change the motion of an object. a clear reading of his first law tells us that what is
    10·1 answer
  • Unpolarized light is passed through an optical filter that is oriented in the vertical direction. 1) If the incident intensity o
    8·1 answer
  • I can raise a bucket of cement mix of mass 12kg through a vertical height of 8m in 10 seconds.Calculate the average power used i
    5·1 answer
  • Which of the following types of technologies has best helped scientists to study very high-energy objects in outer space, such a
    15·2 answers
  • A box exerts a force of 540 N onto the floor and the bottom of the box is 0.5 m2. What is the pressure the box exerts on the flo
    7·2 answers
  • A car travels 60 km in the first 2 hours and 68 km in the next 2 hours. what is the cars average speed ?
    10·1 answer
  • You are driving home from school steadily at 95 km/h for 130 km. During raining, you begin to
    8·1 answer
  • Acceleration can occur when a car is moving at a constant speed. what must cause this acceleration?​
    12·1 answer
  • How does fabric softener help prevent static electricity?
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!