8750 J of heat are applied to a piece of aluminium causing a 56C increase in its

How do you calculate energy lost due to friction in an experiment?

Snowcat [4.5K]

Answer:

A treadmill get it? but its Ff * d cos theta

Explanation:

6 0

3 years ago

How can the frequency with which the direction of a current changes be regulated?

sesenic [268]

Answer:

In an inductive circuit, when frequency increases, the circuit current decreases and vice versa.

Explanation:

5 0

3 years ago

Starting from rest, a disk rotates about its central axis with constant angular acceleration. in 6.00 s, it rotates 44.5 rad. du

Klio2033 [76]

a. The disk starts at rest, so its angular displacement at time $t$ is

$\theta=\dfrac\alpha2t^2$

It rotates 44.5 rad in this time, so we have

$44.5\,\mathrm{rad}=\dfrac\alpha2(6.00\,\mathrm s)^2\implies\alpha=2.47\dfrac{\rm rad}{\mathrm s^2}$

b. Since acceleration is constant, the average angular velocity is

$\omega_{\rm avg}=\dfrac{\omega_f+\omega_i}2=\dfrac{\omega_f}2$

where $\omega_f$ is the angular velocity achieved after 6.00 s. The velocity of the disk at time $t$ is

$\omega=\alpha t$

so we have

$\omega_f=\left(2.47\dfrac{\rm rad}{\mathrm s^2}\right)(6.00\,\mathrm s)=14.8\dfrac{\rm rad}{\rm s}$

making the average velocity

$\omega_{\rm avg}=\dfrac{14.8\frac{\rm rad}{\rm s}}2=7.42\dfrac{\rm rad}{\rm s}$

Another way to find the average velocity is to compute it directly via

$\omega_{\rm avg}=\dfrac{\Delta\theta}{\Delta t}=\dfrac{44.5\,\rm rad}{6.00\,\rm s}=7.42\dfrac{\rm rad}{\rm s}$

c. We already found this using the first method in part (b),

$\omega=14.8\dfrac{\rm rad}{\rm s}$

d. We already know

$\theta=\dfrac\alpha2t^2$

so this is just a matter of plugging in $t=12.0\,\mathrm s$ . We get

$\theta=179\,\mathrm{rad}$

Or to make things slightly more interesting, we could have taken the end of the first 6.00 s interval to be the start of the next 6.00 s interval, so that

$\theta=44.5\,\mathrm{rad}+\left(14.8\dfrac{\rm rad}{\rm s}\right)t+\dfrac\alpha2t^2$

Then for $t=6.00\,\rm s$ we would get the same $\theta=179\,\rm rad$ .

7 0

3 years ago

When traveling on narrow mountain roads _______________. A. honk your horn if you cannot see at least 200 ft ahead B. expect oth

yarga [219]

Answer:

The correct option is;

A. honk your horn if you cannot see at least 200 ft ahead

Explanation:

According the California Driver Handbook on Safe Driving Practices, it is required of the driver driving on a narrow mountain road without clear visualization of what is 200 ft ahead of her or him to honk the horn of the vehicle.

The sounding of the horn will alert those ahead of the driver of the possible danger due to her or his oncoming vehicle so that they (those ahead of the driver's oncoming vehicle) can react appropriately.

6 0

3 years ago

Which of these materials is the most malleable?

trapecia [35]

Malleable basically means bendable and shapeable. notebook paper is the easiest to bend and shape

3 0

3 years ago

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