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3 years ago

The 480 g bar is rotating as shown what is the angular momentum of the bar about the axle?

1 answer:

4 0

On a similar problem wherein instead of 480 g, a 650 gram of bar is used:

Angular momentum L = Iω, where
I = the moment of inertia about the axis of rotation, which for a long thin uniform rod rotating about its center as depicted in the diagram would be 1/12mℓ², where m is the mass of the rod and ℓ is its length. The mass of this particular rod is not given but the length of 2 meters is. The moment of inertia is therefore 
I = 1/12m*2² = 1/3m kg*m² 

The angular momentum ω = 2πf, where f is the frequency of rotation. If the angular momentum is to be in SI units, this frequency must be in revolutions per second. 120 rpm is 2 rev/s, so 
ω = 2π * 2 rev/s = 4π s^(-1) 

The angular momentum would therefore be 
L = Iω 
= 1/3m * 4π 
= 4/3πm kg*m²/s, where m is the rod's mass in kg. 

The direction of the angular momentum vector - pseudovector, actually - would be straight out of the diagram toward the viewer. 

Edit: 650 g = 0.650 kg, so 
L = 4/3π(0.650) kg*m²/s 
≈ 2.72 kg*m²/s

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A treasure map instructs you to walk (25.0+A) m south, followed by (18.0+B) m east, then 64.5 m north, and finally 28.5 m east.

adelina 88 [10]

Answer:

Explanation:

Check attachment for solutions

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3 years ago

Current flowing in a circuit depends on two variables. Identify these variables and their relationship to current.

Nuetrik [128]

Wow ! This question reads like it might have come from one of
Faraday or Maxwell's original laboratory notebooks.

Choice-A is the correct one, when you consider what "conductance"
means. Conductance is just 1/resistance .

So when you see
"A) Current is proportionate to the conductance of the circuit and
precisely proportional to the voltage applied across the circuit."

what it's saying is
"Current is inversely proportional to the resistance of the circuit, and
directly proportional to the voltage applied across the circuit."

If you write the equation for all those words, it looks like

I = V / R

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5 0

4 years ago

Read 2 more answers

The record distance in the sport of throwing cowpats is 81.1 m. This record toss was set by Steve Urner of the United States in

N76 [4]

Answer:

28.2 m/s

Explanation:

The range of a projectile launched from the ground is given by:

$d=\frac{v^2}{g}sin 2\theta$

where

v is the initial speed

g = 9.8 m/s^2 is the acceleration of gravity

$\theta$ is the angle at which the projectile is thrown

In this problem we have

d = 81.1 m is the range

$\theta=45^{\circ}$ is the angle

Solving for v, we find the speed of the projectile:

$v=\sqrt{\frac{dg}{sin 2 \theta}}=\sqrt{\frac{(81.1 m)(9.8 m/s^2)}{sin (2\cdot 45^{\circ})}}=28.2 m/s$

7 0

3 years ago

To start an avalanche on a mountain slope, an artillery shell is fired with an initial velocity of 290 m/s at 57.0° above the ho

cupoosta [38]

Answer:

xf = 5.68 × 10³ m

yf = 8.57 × 10³ m

Explanation:

given data

vi = 290 m/s

θ = 57.0°

t = 36.0 s

solution

firsa we get here origin (0,0) to where the shell is launched

xi = 0 yi = 0

xf = ? yf = ?

vxi = vicosθ vyi = visinθ

ax = 0 ay = −9.8 m/s

now we solve x motion: that is

xf = xi + vxi × t + 0.5 × ax × t² ............1

simplfy it we get

xf = 0 + vicosθ × t + 0

put here value and we get

xf = 0 + (290 m/s) cos(57) (36.0 s)

xf = 5.68 × 10³ m

and

now we solve for y motion: that is

yf = yi + vyi × t + 0.5 × ay × t ² ............2

put here value and we get

yf = 0 + (290 m/s) × sin(57) × (36.0 s) + 0.5 × (−9.8 m/s2) × (36.0 s) ²

yf = 8.57 × 10³ m

5 0

4 years ago

The only two forces acting on a body have magnitudes of 20 N and 35 N and directions that differ by 80°. The resulting accelerat

pantera1 [17]

Answer:

b) 2.2 kg

Explanation:

Net force acting on an object is the sum of the two forces acting on the body.

The net force is calculated using the parallelogram law of vectors.

F = $\sqrt{{A^{2}} + B^{2}+2 A B cos \theta}$

Here A = 20 N , B = 35 N and θ =80°

Net Force = F = 43.22 N

Acceleration = a = 20 m/s/s

Since F = ma, m = F/a = 43.22 / 20 = 2.161 kg = 2.2 kg

8 0

3 years ago