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3 years ago

The kinetic energy of the pendulum bob in figure 15-1 increases the most between locations

Physics

2 answers:

Ket [755]3 years ago

7 0

Answer:A and C

Explanation:

Fudgin [204]3 years ago

3 0

Answer:

A and C

Explanation:

Kinetic energy of a body is given by the expression, $KE =\frac{1}{2}mv^2$ , where v is the velocity and m is the mass of body.

In case of a simple pendulum the maximum velocity is at it's stationary position.

So maximum velocity i at position C, which means maximum kinetic energy is at position A.

The velocity of pendulum reduces as the angle between vertical stationary and current position increases.

So, velocity at E and A are the minimum, so at A and E the kinetic energy value is minimum.

Now examining the options given, we will understand the kinetic energy increase is maximum in case of A and C.

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9) A bug of mass 0.020 kg is at rest on the edge of a solid cylindrical disk (M = 0.10 kg, R = 0.10 m) rotating in a horizontal

natima [27]

Answer:

a. ω₂ = 14rad/s

b. ∇K.E = 0.014J

c. The bug does not conserve force while moving on the disk (non-conservative force).

Explanation:

Mass of the bug (m) = 0.02kg

Mass of the cylindrical disk (M) = 0.10kg

Radius of the disk (r) = 0.10m

Initial angular velocity ω₁ = 10rad/s

final angular velocity ω₂ = ?

To calculate the new angular velocity, we relate it to the conservation of angular momentum of the system I.e when the bug was at the edge of the disk and when it is located at the centre of the disk.

I = Mr² / 2

I₁ = Mr₂ / 2 + mr²

I₁ = moment of inertia when the bug was at the edge

I₁ = [(0.10 * 0.10²) / 2 ] + (0.02 * 0.1²)

I₁ = 0.0005 + 0.0002

I₁ = 7.0*10⁻⁴kgm²

I₂ = moment of inertia when yhe bug was at the center of the disk.

I₂ = Mr² / 2

I₂ = (0.01 * 0.01²) 2

I₂ = 0.0005kgm²

for conservation of angular momentum,

I₁ω₁ = I₂ω₂

solve for ω₂

ω₂ = (I₁ * ω₁) / I₂

ω₂ = (7.0*10⁻⁴ * 10) / 5.0*10⁻⁴

ω₂ = 14 rad/s

b. the change in kinetic energy of the system is

∇K = K₂ - K₁

∇K = ½I₂*ω₂² - ½I₁*ω₁²

∇K = ½(I₂*ω₂² - I₁ω₁²)

∇K = ½[(5.0*10⁻⁴ * 14²) - (7.0*10⁻⁴ * 10²)]

∇k = ½(0.098 - 0.07)

∇K = ½ * 0.028

∇K = 0.014J

The cause of the decrease and increase in kinetic energy is because the bug uses a non-conservative force. To conserve the mechanical energy of a system, all the forces acting in it must be conservative.

The work W produced by this force brings the difference in kinetic energy of the system

W = K₂ - K₁

6 0

3 years ago

A force of 30 N is applied tangentially to the rim of a solid disk of radius 0.14 m. The disk rotates about an axis through its

jenyasd209 [6]

Answer:

3.8 kg

Explanation:

The torque, τ, due to the force, F, is given by

$\tau = F\times r$

where r is the radius.

This torque is also given by

$\tau = I\times\alpha$

where I and α are respectively the moment of inertia and the angular acceleration.

For a solid disk, its moment of inertia for an axis though its centre and perpendicular to its face is given by

$I = \frac{1}{2}mr^2$

where m is its mass and r is its radius.

Hence, we have

$\tau = F\times r = I\times\alpha=\frac{1}{2}mr^2\times\alpha$

$m = \dfrac{2F}{r\alpha} = \dfrac{2(30\ \text{N})}{(0.14\ \text{m})(115\ \text{rad/s}^2)} = 3.8\ \text{kg}$

5 0

3 years ago

Read 2 more answers

Electromagnetic waves can travel through empty space true or false

Mariana [72]

False. Heat radiation from the sun cannot reach Earth, we cannot receive TV or GPS signals from satellites, and we cannot detect the light from distant stars.
Oh, wait . . .

6 0

3 years ago

The position-time graph for a bug crawling along a line is shown in item 4 below. Determine whether the velocity is positive, ne

Naddika [18.5K]

Answer: The velocity at different marked time points are given as

t1 = -

t2 = +

t3 = +

t4 = -

t5 = 0

Explanation:

The slope of the tangent of the curve indicates the instantaneous velocity. So if the slope of the tangent is positive, that Is, the tangent makes a positive angle (above the horizontal axis) with the horizontal

axis, then the velocity at this point is positive, and if the slope of the tangent is negative, that is the tangent makes a negative angle with the horizontal axis (below the horizontal axis), then the velocity at this point is negative.

When the tangent of the line is parallel to the horizontal axis, the velocity is 0.

From the position-time graph attached, the sign on the instantaneous velocity for each time marked on the graph is given below

t1 = -

t2 = +

t3 = +

t4 = -

t5 = 0

QED!

5 0

3 years ago

Let this oscillator have the same energy as a mass on a spring, with the same k and m, released from rest at a displacement of 5

allochka39001 [22]

There are a lot of same examples that you may have worked before, where the mass on a spring uses a classics when it comes to mechanics. So in this system, always put in your mind that there is an enormous quantum standard that one can use in the equation. It should be 2.10x10 raise to a negative sixth. J.

3 0

3 years ago