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algol13
2 years ago
14

A uniform disk has a mass of 3.7 kg and a radius of 0.40 m. The disk is mounted on frictionless bearings and is used as a turnta

ble. The turntable is initially rotating at 30 rpm. A thin-walled hollow cylinder has the same mass and radius as the disk. It is released from rest, just above the turntable, and on the same vertical axis. The hollow cylinder slips on the turntable for 0.20 s until it acquires the same final angular velocity as the turntable. What is the final angular momentum of the system
Physics
1 answer:
yuradex [85]2 years ago
5 0

Answer:

1.25 kgm²/sec

Explanation:

Disk inertia, Jd =

Jd = 1/2 * 3.7 * 0.40² = 0.2960 kgm²

Disk angular speed =

ωd = 0.1047 * 30 = 3.1416 rad/sec

Hollow cylinder inertia =

Jc = 3.7 * 0.40² = 0.592 kgm²

Initial Kinetic Energy of the disk

Ekd = 1/2 * Jd * ωd²

Ekd = 0.148 * 9.87

Ekd = 1.4607 joule

Ekd = (Jc + 1/2*Jd) * ω²

Final angular speed =

ω² = Ekd/(Jc+1/2*Jd)

ω² = 1.4607/(0.592+0.148)

ω² = 1.4607/0.74

ω² = 1.974

ω = √1.974

ω = 1.405 rad/sec

Final angular momentum =

L = (Jd+Jc) * ω

L = 0.888 * 1.405

L = 1.25 kgm²/sec

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frosja888 [35]

Answer:

t=0.704s

Explanation:

A child is running his 46.1 g toy car down a ramp. The ramp is 1.73 m long and forms a 40.5° angle with the flat ground. How long will it take the car to reach the bottom of the ramp if there is no friction?

from newton equation of motion , we look for the y component of the speed and look for the x component of the speed. we can then find the resultant of the speed

V^{2} =u^{2} +2as

Vy^2=0+2*9.8*1.73sin40.5

Vy^2=22.021

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Vx^2=u^2+2*9.81*cos40.5

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V=47.71^0.5

V=6.9m/s

from newtons equation of motion we know that force applied is directly proportional to the rate of change in momentum on a body.

f=force applied

v=velocity final

u=initial velocity

m=mass of the toy, 0.046

f=ma

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4 0
2 years ago
A succession of single tones or pitches perceived as a unit is called:
jeka57 [31]
A succession of single tones or pitches perceived as a unit is called a melody. It is a linear succesion of tones in music that is seen as one single entity. It is a combination of rhythm, pitch and tonal color. Melodies usually has one ormore motifs or phrases that are being repeated all throughout a composition. Melodies are characterized by the melodic motion it posses , the pitch, intervals between the pitches, continuity and pitch range. Due to the a wide range of melodies that can be made from tones, differet genres of music arise. Examples are Jazz, Rock music, Classical, pop, R&B and the like. 
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A straight wire carries a current of 3 A which is in the plane of this page, pointed toward the top of the page. A particle of c
Ilia_Sergeevich [38]

Answer:

The magnitude of the magnetic force exerted on the moving charge by the current in the wire is 2.18 x 10^{-8} N

The direction of the magnetic force exerted on the moving charge by the current in the wire is radially inward

Explanation:

given information:

current, I = 3 A

q_{0} = +6.5 x 10^{-6} C

r = 0.05 m

v = 280 m/s

and direction of the magnetic force exerted on the moving charge by the current in the wire, we can use the following formula:

F = qvB sin θ

where

F = magnetic force (N)

q = electric charge (C)

v = velocity (m/s)

θ = the angle between the velocity and magnetic field

to find B we use

B = μ_{0}I/2πr

μ_{0} = 4π x 10^{-7} or 1.26 x 10^{-6} N/A^{2} , thus

B = 4π x 10^{-7} x 3 / 2π(0.05)

  = 1.2  x  10^{-5} T

Now, we can calculate the magnitude force

F = qvB sin θ

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Answer:

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At the moment of touching the hand, a relationship is applied that reverses the value of the speed, that is, now it is ascending and the cycle repeats.

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Gala2k [10]

Answer:

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Explanation:

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2 years ago
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