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2 years ago

The motor of a washing machine rotates with a period of 28 ms. What is the angular speed, in units of rad/s?

Physics

1 answer:

pentagon [3]2 years ago

5 0

Answer:

2π/[28 x (10^-3)]

Explanation:

Angular speed : ω=2π/T

T = 28ms = 28 x (10^-3) s

Angular speed = 2π/[28 x (10^-3)]

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A solid cylinder of mass 12.0 kgkg and radius 0.250 mm is free to rotate without friction around its central axis. If you do 75.

dybincka [34]

Answer:

The final angular velocity is 20rad/s

Explanation:

We are given;

mass, m = 12 kg

radius, r = 0.25 m

Work done;W = 75 J

Moment of inertia of cylinder, I = (1/2) mr²

Thus,

I = (1/2) x 12 x 0.25² = 0.375 kg.m²

Now, from work energy theorem,

Work done = Change in kinetic energy

So, W = KE_f - KE_i

Now, Initial Kinetic Energy (KE_i) = 0

Final Kinetic Energy; KE_f = (1/2)Iω²

So, KE_f = (1/2) x 0.375 x ω²

KE_f = 0.1875 ω²

Now, W = 75 J

Thus,

From, W = KE_f - KE_i, we have;

75 = 0.1875 ω² - 0

75 = 0.1875 ω²

ω² = 75/0.1875

ω² = 400

ω = √400

ω = 20 rad/s

5 0

2 years ago

A boy is whirling a stone around his head by means of a string. The string makes one complete revolution every second; and the m

Damm [24]

Answer

given,

Tension of string is F

velocity is increased and the radius is not changed.

the string makes two complete revolutions every second

consider the centrifugal force acting on the stone

= $\dfrac{mv^2}{r}$

now centrifugal force is balanced by tension

T = $\dfrac{mv^2}{r}$

From the above expression we can clearly see that tension is directly proportional to velocity and inversely proportional to radius.

When radius is not changing velocity is increasing means tension will also increase in the string.

8 0

2 years ago

At a rock concert, the sound intensity 1.0 m in front of the bank of loudspeakers is 0.10 W/m2. A fan is 30 m from the loudspeak

aliina [53]

Explanation:

Below is an attachment containing the solution.

5 0

2 years ago

In what direction would the particles in this wave move, relative to the direction of wave travel?

Setler79 [48]

Everywhere particles dont stay in one place they move elsewhere

7 0

2 years ago

Read 2 more answers

You are piloting a helicopter which is rising vertically at a uniform velocity of 14.70 m/s. When you reach 196.00 m, you see Ba

Cloud [144]

Answer:

The ball reaches Barney head in $t = 8 \ s$

Explanation:

From the question we are told that

The rise velocity is $v = 14.70 \ m/s$

The height considered is $h = 196 \ m$

The horizontal velocity of the large object is $v_h = 8.50 \ m/s$

Generally from kinematic equation

$s = ut + \frac{1}{2} gt^2$

Here s is the distance of the object from Barney head ,

u is the velocity of the object along the vertical axis which is equal but opposite to the velocity of the helicopter

$u = -14.7 m/s$

$196 = -14.7 t + \frac{1}{2} * 9.8 * t^2$

= $4.9 t^2 - 14.7t - 196 = 0$

Solving the above equation using quadratic formula

The value of t obtained is $t = 8 \ s$

6 0

2 years ago