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3 years ago

This is about resistance, voltage, currentany answers greatly appreciated

Physics

1 answer:

guapka [62]3 years ago

6 0

Current is a flow of electrical charge carriers, usually electrons or electron-deficient atoms. ... Physicists consider current to flow from relatively positive points to relatively negative points; this is called conventional current or Franklin current. Electrons, the most common charge carriers, are negatively charged.
Voltage is electric potential energy per unit charge, measured in joules per coulomb ( = volts). It is often referred to as "electric potential", which then must be distinguished from electric potential energy by noting that the "potential" is a "per-unit-charge" quantity.

The electrical resistance of a circuit component or device is defined as the ratio of the voltage applied to the electric current whichflows through it: If the resistance is constant over a considerable range of voltage, then Ohm's law, I = V/R, can be used to predict the behavior of the material.b

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A spherical object has a density rho. If it is compressed under high pressure to one third of its original diameter, its density

Ne4ueva [31]

Answer:

e. 27 rho.

Explanation:

The density of an object, assumed constant, is defined as the relationship between the mass and the volume.

If the object is compressed in such a way that the diameter is reduced to 1/3, this means, that the radius will be reduced in the same proportion.

Now, if the mass remains the same (the compression can't change it) , the volume (assumed to be a perfect sphere) will be reduced also:

V₀ = 4/3*π*r³

Vf= 4/3*π*(r/3)³ = 4/3*π*(r³/27) = V₀/27

As the volume is in in the denominator of the expression for density, this means that the new density will be equal to 27 times the original one:

ρ₀ = m/ V₀

ρ₁ = m/ V₁ = m/ (V₀/27) = 27* (m/V₀) = 27*ρ₀

8 0

4 years ago

A basketball player wishes to make a stunning last-second basket. With .8 seconds on the clock, she wants the ball to enter the

zheka24 [161]

Answer:

(1) $46.86^\circ$

(2) Diagram has been attached in the solution.

Explanation:

This question is from projectile motion.

From the given question, we will discuss the motion of the basket ball only in the vertical direction from which we will be able to find out the angle of the initial velocity with the horizontal with which it should be shoot to enter the hoop.

Part (1):

Let us assume:

$y_i$ = initial position of the basket ball = 2.1 m
$y_f$ = final position of the basket ball = 3.05 m
$a_y$ = acceleration of the ball along the vertical = $-9.8\ m/s^2$
$t$ = time taken to reach the goal = 0.8 s
$\theta$ = angle of the initial velocity with the horizontal
$u$ = initial speed of the ball = 7 m/s
$u_y$ = initial vertical velocity of the ball = u\sin \theta

Using the equation of motion for constant acceleration, we have

$y_f-y_i=u_yt+\dfrac{1}{2}a_yt^2\\\Rightarrow 3.05-2.1=u\sin \theta (0.8) +\dfrac{1}{2}\times (-9.8)(0.8)^2\\\Rightarrow 0.95=7\times \sin \theta (0.8) -3.136\\\Rightarrow 0.95=5.6\sin \theta -3.136\\\Rightarrow 5.6\sin \theta= 0.95+3.136\\\Rightarrow 5.6\sin \theta= 4.086\\\Rightarrow \sin \theta= \dfrac{4.086}{5.6}\\\Rightarrow \sin \theta=0.729\\\Rightarrow \theta=\sin^{-1}(0.729)\\\Rightarrow \theta=46.86^\circ$

Hence, the angle of the shoot of the basket ball with the horizontal is $46.86^\circ$ such that it reaches the hoop on time.

Part (2):

For this part, a diagram has been attached.

4 0

3 years ago

A 1000 kg satellite and a 2000 kg satellite follow exactly the same orbit around the earth. What is the ratio F1/F2 of the gravi

Tamiku [17]

Answer:

the ratio F1/F2 = 1/2

the ratio a1/a2 = 1

Explanation:

The force that both satellites experience is:

F1 = G M_e m1 / r² and

F2 = G M_e m2 / r²

where

m1 is the mass of satellite 1
m2 is the mass of satellite 2
r is the orbital radius
M_e is the mass of Earth

Therefore,

F1/F2 = [G M_e m1 / r²] / [G M_e m2 / r²]

F1/F2 = [G M_e m1 / r²] × [r² / G M_e m2]

F1/F2 = m1/m2

F1/F2 = 1000/2000

F1/F2 = 1/2

The other force that the two satellites experience is the centripetal force. Therefore,

F1c = m1 v² / r and

F2c = m2 v² / r

where

m1 is the mass of satellite 1
m2 is the mass of satellite 2
v is the orbital velocity
r is the orbital velocity

Thus,

a1 = v² / r ⇒ v² = r a1 and

a2 = v² / r ⇒ v² = r a2

Therefore,

F1c = m1 a1 r / r = m1 a1

F2c = m2 a2 r / r = m2 a2

In order for the satellites to stay in orbit, the gravitational force must equal the centripetal force. Thus,

F1 = F1c

G M_e m1 / r² = m1 a1

a1 = G M_e / r²

also

a2 = G M_e / r²

Thus,

a1/a2 = [G M_e / r²] / [G M_e / r²]

a1/a2 = 1

4 0

3 years ago

3. What is the temperature if a 545-Hz sound wave has a wavelength of 0.651 m

KATRIN_1 [288]

Answer:

19.33°C

Explanation:

To find the value of T you use the following formula:

$v=343+0.61T$

v: speed of sound

To calculate v you use:

$v=\lambda f$

λ: wavelength = 0.651m

f: = 545Hz

by replacing :

$v=(0.651m)(545s^{-1})=354.79m/s$

Finally, by replacing in the first formula you obtain:

$354.79=343+0.61T\\\\T=19.33\°C$

T = 19.33°C

7 0

3 years ago

What force cause the rod to become charged

gtnhenbr [62]

Answer:

electricity

If a rod is charged it is because of the electrical force acting on it

6 0

3 years ago