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Anuta_ua [19.1K]

3 years ago

8

A 1.20 g sample of an unknown has a volume of 1.73 cm what is the density of the unknown

1 answer:

mariarad [96]3 years ago

7 0

1.73 divide by 1.20=1.4416

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;-; please help me....

sineoko [7]

The answer is 24N. Since the body is moving with constant velocity all the forces must balance (equal & opposite)

5 0

2 years ago

A solid, horizontal cylinder of mass 18.0 kg and radius 1.70.0 m rotates with an angular speed of 40 rad/s about a fixed vertica

Radda [10]

Answer:39.88 rad/s

Explanation:

Given

mass of cylinder m_1=18 kg

radius R=1.7 m

angular speed $\omega =40rad/s$

mass of $m_2=0.8 kg$ dropped at r=0.3 m from center

let $\omega _2$ be the final angular velocity of cylinder

Conserving Angular momentum

$L_1=L_2$

$\left ( \frac{m_1R^2}{2}\right )\omega =\left ( \frac{m_1R^2}{2}+m_2r^2\right )\omega _2$

$\left ( \frac{18\cdot 1.7^2}{2}\right )\cdot 40=\left ( \frac{18\cdot 1.7^2}{2}+0.8\cdot 0.3^2\right )\omega _2$

$26.01\times 40=26.082\times \omega _2$

$\omega _2=39.88 rad/s$

3 0

3 years ago

Which of the following is typically NOT a method scientist use to determine astronomic distances

tangare [24]

I think the answer is A

5 0

3 years ago

The auto in the sketch moves forward as the brakes are applied. A bystander says that during the interval of braking, the auto's

Ivan

Answer:

The statement is true: velocity and acceleration have opposite directions in the interval of braking.

Explanation:

Let's say we have a velocity $v>0$ .

The acceleration $a$ is the rate of change of the velocity $v$ . This means that if $v$ is <em>increasing during</em> time, then $a$ must be positive. But if $v$ is <em>decreasing over</em> time, then $a$ will be negative (even though the velocity is positive).

Mathematically:

$a=\frac{dv}{dt}$

$v$ decreases ⇒ $\frac{dv}{dt}$

⇒ $a$ .

Example:

$v(t)=e^{-t}>0 \\\\\frac{dv}{dt}=-te^{-t}$

3 0

3 years ago

A constant magnetic field passes through a single rectangular loop whose dimensions are 0.35 m × 0.55 m. The magnetic field has

Pani-rosa [81]

Answer:

Part a)

$EMF = 0.38 V$

Part b)

$\frac{dA}{dt} = 0.43 m^2/s$

Explanation:

Part a)

Initial value of magnetic flux is given as

$\phi_1 = BAcos\theta$

$\phi_1 = (2.1)(0.35 \times 0.55) cos65$

so we have

$\phi_1 = 0.17 Wb$

Final flux through the loop is given as

$\phi_2 = 0$

now EMF is given as

$EMF = \frac{\phi_1 - \phi_2}{\Delta t}$

$EMF = \frac{0.17 - 0}{0.45}$

$EMF = 0.38 V$

Part b)

If magnetic field is constant while Area is changing

So EMF is given as

$E = Bcos65 \times \frac{dA}{dt}$

$0.38 = 2.1 cos65(\frac{dA}{dt})$

$\frac{dA}{dt} = 0.43 m^2/s$

5 0

2 years ago