Who is the first president of China ?

When an object (like a ball) falls, some of its___ energy changes to ___ energy, due to the law of conservation of energy

Alinara [238K]

Answer:

potential, kinetic

Explanation:

pls give brainliest :p

8 0

2 years ago

A solenoid with 35 turns per centimeter carries a current I. An electron moves within the solenoid in a circle that has a radius

castortr0y [4]

Answer:

The current of the solenoid is 0.0129 A.

Explanation:

The movement of the electron within the solenoid in a circle is produced by equaling the magnetic force and the centripetal force, as follows:

$F_{B} = F_{c}$

$e*v \mu_{0}*n*I = \frac{m*v^{2}}{r}$

$I = \frac{m*v}{e* \mu_{0}*n*r}$

Where:

I: is the current

m: is the electron's mass = 9.1x10⁺³¹ kg

v: is the electron's speed = 3.0x10⁵ m/s

μ₀: is the permeability magnetic = 4πx10⁻⁷ T.m/A

n: is the number of turns per unit length = 35/cm

r: is the radius of the circle = 3.0 cm

e: is the electron's charge = 1.6x10⁻¹⁹ C

$I = \frac{m*v}{e*\mu_{0}*n*r} = \frac{9.1 \cdot 10^{-31} kg*3.0 \cdot 10^{5} m/s}{1.6 \cdot 10^{-19} C*4\pi \cdot 10^{-7} T.m/A*3500/m*0.03 m} = 0.0129 A$

Therefore, the current of the solenoid is 0.0129 A.

I hope it helps you!

3 0

3 years ago

A wheel accelerates from rest to 34.7 rad/s at a rate of 47.0 rad/s^2. Through what angle (in radians) did the wheel turn while

dem82 [27]

12.8 rad

Explanation:

The angular displacement $\theta$ through which the wheel turned can be determined from the equation below:

$\omega^2 = \omega_0^2 + 2\alpha\theta$ (1)

where

$\omega_0 = 0$

$\omega = 34.7\:\text{rad/s}$

$\alpha = 47.0\:\text{rad/s}^2$

Using these values, we can solve for $\theta$ from Eqn(1) as follows:

$2\alpha\theta = \omega^2 - \omega_0^2$

or

$\theta = \dfrac{\omega^2 - \omega_0^2}{2\alpha}$

$\:\:\:\:= \dfrac{(34.7\:\text{rad/s})^2 - 0}{2(47.0\:\text{rad/s}^2)}$

$\:\:\:\:= 12.8\:\text{rad}$

7 0

2 years ago

the scores of players on a golf team are shown in the table. the teams combined score was 0 what was travis's score?

Alona [7]

Answer:

what table?

Explanation:

3 0

3 years ago

Read 2 more answers

A concert loudspeaker suspended high off the ground emits 34 W of sound power. A small microphone with a 1.0 cm2 area is 44 m fr

rjkz [21]

Answer:

Part A

I = 1.4 mW/m²

Part B

β = 91.46 dB

Explanation:

Part A

Sound intensity is the power per unit area of sound waves in a direction perpendicular to that area. Sound intensity is also called acoustic intensity.

For a spherical sound wave, the sound intensity is given by;

$I = \frac{P}{A}$

$I = \frac{P}{4\pi r^{2}}$

Where;

P is the source of power in watts (W)

I is the intensity of the sound in watt per square meter (W/m2)

r is the distance r away

Given:

P = 34 W,

A = 1.0 cm²

r = 44 m

The sound intensity at the position of the microphone is calculated to be;

$I = \frac{34}{4\pi (44)^{2}}$

I = 0.0013975 W/m²

≈ I = 0.0014 W/m² = 1.4 × 10⁻³ W/m²

I = 1.4 mW/m²

The sound intensity at the position of the microphone is 1.4 mW/m².

Part B

Sound intensity level or acoustic intensity level is the level of the intensity of a sound relative to a reference value. It is a a logarithmic quantity. It is denoted by β and expressed in nepers, bels, or decibels.

Sound intensity level is calculated as;

β $= 10log_{10}\frac{I}{I_{0}}$ dB

Where,

β is the Sound intensity level in decibels (dB)

I is the sound intensity;

I₀ is the reference sound intensity;

By pluging-in, I₀ is 1.0 × 10⁻¹² W/m²

∴ β $= 10log_{10}\frac{1.4 * 10^{-3} W/m^{2}}{1.0 * 10^{-12} W/m^{2}}$

β $= 10log_{10} (1.4 * 10^{9})$

β = 91.46 dB

The sound intensity level at the position of the microphone is 91.46 dB.

4 0

3 years ago