Which of the following is a physical change?

How far apart must two protons be if the electrical force acting on either one is equal to its weight on the earth's surface whe

BARSIC [14]

Answer:

G M m / R^2 = F force of attraction for proton

K e^2 / r^2 = F force of attraction between 2 protons

G M m / R^2 = K e^2 / r^2

r^2 = K e^2 R^2 / (G M m)

r^2 = 9E9 * (1.6E-19)^2 * (6.37E6)^2 / (6.67E-11 * 5.98E24 * 1.7E-27)

r^2 = 9 * 2.56 * 40.6 / (6.67 * 5.98 * 1.7) * 10^-19

r^2 = 1.38 * 10^-30

r = 1.17E-15 m

7 0

3 years ago

A long solenoid with 8.22 turns/cm and a radius of 7.00 cm carries a current of 19.4 mA. A current of 3.59 A exists in a straigh

daser333 [38]

Answer:

a. 3.039cm

b.magnetic field is $B=2.958\times10^{-5}T$

Explanation:

Direction of the solenoid magnetic field is along the axis of the solenoid. and magnetic field due to the wire perpendicular to that due to the solenoid.. Magnetic field at r is given by:

$\overrightarrow B = \overrightarrow B_s+ \overrightarrow B_w,\ \ \ \ \ \overrightarrow B_s\perp \overrightarrow B_w$

Angle of net magnetic field from axial direction is given by:

$tan\ \theta=\frac{B_w}{B_s}$ ,

Field due to solenoid:

$B_s=\mu_onI_s, \ \ \ \ n=(8.22 t/cm)(100cm/m)=822turn/m$

Field due to wire:

$B_w=\frac{\mu_oI_w}{2\pi r}$

Therefore, r:

$tan\ \theta=\frac{B_w}{B_s}\\\\=\frac{\mu_oI_w}{2\pi r(\mu_o nI_s)}\\\\r=\frac{I_w}{2\pi nI_stan \ \theta}\\\\r=\frac{3.59A}{2\pi\times822\times19.4\times10^{-3}A \ tan 49.7\textdegree}\\\\r=3.039cm$

Hence, the radial distance is 3.039cm

b.The magnetic field strength is given by:

$B=\sqrt{B_w^2+B_s^2}\\\\tan 49.7\textdegree=\frac{B_w}{B_s}\\\\1.179=\frac{B_w}{B_s}\\\\B_w=1.179B_s\\\\B=\sqrt{(4\pi\times10^{-7}T.m/A\times 822\times19.4\times10^{3}A)+1.179(4\pi\times10^{-7}T.m/A\times 822\times19.4\times10^{-3}A)}\\\\B=2.958\times10^{-5}T$

Hence, the magnetic field is $B=2.958\times10^{-5}T$

7 0

4 years ago

Larry , Moe, and Curly are pushing on a 25 kg crate. The crate is sitting on a horizontal floor, and the coefficient of kinetic

monitta

Answer:

2 m/s².

Explanation:

The forces acting on the crate have been shown in the figure below.

Net force acting on the crate in the horizontal direction = 400 - 250 = 150 N towards right.

For the forces of vertical direction we can write,

Normal force = 150 + Mg = 150 + 250 = 400 N (here g = 10 m/s² have been taken)

The magnitude of frictional force that will act on the crate = μ × Normal force

So, Frictional force = 0.25 × 400 = 100 N

Thus, the net force that will cause acceleration in the crate will be

Force in the right direction - frictional force

= 150 - 100 = 50 N

As we know,

Acceleration = $\frac{Force}{Mass}$ = $\frac{50}{25}$ = 2 m/s²

So, the net acceleration in the crate will be 2 m/s².

7 0

4 years ago

Help please is for today

stellarik [79]

Answer:

malabo Hindi makita i don't know what the answer

6 0

3 years ago

Why do astronomers use the astronomical unit to measure distance of the solar system?

Ivahew [28]

An astronomical unit is the measure of the center of the Earth to the center of the sun.

Because our solar system is so vast, using mere miles is ridiculous, because they are too small to be helpful and the numbers will be in the billions. Astronomical units make it easier to think in small amounts.

Hope this helps :)

4 0

3 years ago