Which of the following will change if you apply unbalanced forces to an object?

Kate gathered 3 of the same size made of different materials: glas, clear plastic, and aluminum painted black. She placed on the

Anestetic [448]

Answer:

To relate the type of box material to the warmth inside the box 

Explanation:

3 boxes are made with three different materials glass, plastic and Aluminium. Thermal conductivity is different for different materials. thermal conductors allow easy flow of heat through them and insulators allow minimal or no flow of heat through them.

Thus the amount by which an object gets heated up depends on the value of its conductivity. In this experiment, glass and plastic are insulators and aluminium is a conductor. Among glass and plastic, plastic is a better insulator.

Thus the heat contained in the boxes will be of the order Aluminium>glass>plastic.

3 0

4 years ago

A resistor is connected in series with an AC source that provides a sinusoidal voltage of v of t is equal to V times cosine of b

nekit [7.7K]

<h2>Answer:</h2>

In circuits, the average power is defined as the average of the instantaneous power over one period. The instantaneous power can be found as:

$p(t)=v(t)i(t)$

So the average power is:

$P=\frac{1}{T}\intop_{0}^{T}p(t)dt$

But:

$v(t)=v_{m}cos(\omega t) \\ \\ i(t)=i_{m}cos(\omega t)$

So:

$P=\frac{1}{T}\intop_{0}^{T}v_{m}cos(\omega t)i_{m}cos(\omega t)dt \\ \\ P=\frac{v_{m}i_{m}}{T}\intop_{0}^{T}cos^{2}(\omega t)dt \\ \\ But: cos^{2}(\omega t)=\frac{1+cos(2\omega t)}{2}$

$P=\frac{v_{m}i_{m}}{T}\intop_{0}^{T}(\frac{1+cos(2\omega t)}{2} )dt \\\\P=\frac{v_{m}i_{m}}{T}\intop_{0}^{T}[\frac{1}{2}+\frac{cos(2\omega t)}{2}]dt \\\\P=\frac{v_{m}i_{m}}{T}[\frac{1}{2}(t)\right|_0^T +\frac{sin(2\omega t)}{4\omega} \right|_0^T] \\ \\ P=\frac{v_{m}i_{m}}{2T}[(t)\right|_0^T +\frac{sin(2\omega t)}{2\omega} \right|_0^T] \\ \\ P=\frac{v_{m}i_{m}}{2}$

In terms of RMS values:

$V_{RMS}=V=\frac{v_{m}}{\sqrt{2}} \\ \\ I_{RMS}=I=\frac{i_{m}}{\sqrt{2}} \\ \\ Then: \\ \\ P=VI$

7 0

3 years ago

Extreme tides are... a. extremely rare b. a normal occurrence c. caused only by hurricanes d. not really tides I think the answe

Serjik [45]

Extreme tides happen twice a month. They are caused by the earth, Sun, and Moon all being in a straight alignment. Although they are not extremely rare, extreme tides are not normal occurrences. The answer is D.

7 0

3 years ago

10. There is less pressure when a force is present on a(n)

Nina [5.8K]

What’s the question

6 0

3 years ago

3. El tambor de una lavadora que gira a 3 000 revoluciones por minuto (rpm) se acelera uniformemente hasta que alcanza las 6 000

cestrela7 [59]

Answer:

d) α = 1693.5 rad / s² , a = 392.7 m / s² , a_total = α √(R² +1) ,

e) tan θ = a / α

Explanation:

This is an exercise in linear and angular kinematics.

We initialize reduction of all the magnitudes to the SI system

w₀ = 3000 rev / min (2π rad / 1rev) (1min / 60s) = 314.16 rad / s

w = 6000 rev / mi = 628.32 rad / s

θ = 12 rev = 12 rev (2π rad / 1 rev) = 75.398 rad

d) ask for centripetal, tangential and total acceleration.

Let's start by looking for centripetal acceleration, let's use the formula

w² = w₀² + 2 α θ

α = (w²- w₀²) / 2θ

we calculate

α = (628.32²2 - 314.16²) / 2 75.398

α = 1693.5 rad / s²

the quantity is linear and angular are related

the linear or tangential acceleration is

a = α R

where R is the radius of the drum

a = 1693.5 R

Unfortunately you do not give the radius of the drum for a complete calculation, but suppose it is a washing machine drum R = 20 cm = 0.20 m

a = 1693.5 0.20

a = 392.7 m / s²

the total acceleration is

a_total = √(a² + α²)

a_total = √ (α² R² + α²)

a_total = α √(R² +1)

e) The centripetal acceleration is directed towards the center of the movement is radial and its magnitude is constant

Tangential acceleration is tangency to radius and its value varies proportionally radius

the total accelracicon is the result of the vector sum of the two accelerations and their directions given by trigonometry

tan θ = a / α

the angular velocity increases linearly when with centripetal acceleration

8 0

3 years ago