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3 years ago

A body travels the first half of the total distance with velocity v and second half with v2 calculate avg velocity

Physics

1 answer:

LuckyWell [14K]3 years ago

8 0

Answer:

v = 2 v₁ v₂ / (v₁ + v₂)

Explanation:

The body travels the first half of the distance with velocity v₁. The time it takes is:

t₁ = (d/2) / v₁

t₁ = d / (2v₁)

Similarly, the body travels the second half with velocity v₂, so the time is:

t₂ = (d/2) / v₂

t₂ = d / (2v₂)

The average velocity is the total displacement over total time:

v = d / t

v = d / (t₁ + t₂)

v = d / (d / (2v₁) + d / (2v₂))

v = d / (d/2 (1/v₁ + 1/v₂))

v = 2 / (1/v₁ + 1/v₂)

v = 2 / ((v₁ + v₂) / (v₁ v₂))

v = 2 v₁ v₂ / (v₁ + v₂)

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A. What quantum number of the hydrogen atom comes closest to giving a 61-nm-diameter electron orbit?

Black_prince [1.1K]

Answer:

$n = 23$

$v = 87377.95 \ m/s$

Explanation:

From the question we are told that

The diameter is $d = 61\ nm = 61 *10^{-9} \ m$

Generally the radius electron orbit is mathematically represented as

$r = \frac{61 *10^{-9}}{2}$

=> $r = 3.05*10^{-8} \ m$

This radius can also be represented mathematically as

$r = n^2 * a_o$

Here n is the quantum number and $a_o$ is the Bohr radius with a value

$a_o = 0.0529 *10^{-9} \ m$

$n = \sqrt{\frac{3.05*10^{-8}}{ 0.059*10^{-9}} }$

=> $n = 23$

Generally the angular momentum of the electron is mathematically represented as

$L = m * v * r = \frac{n * h }{2 \pi}$

Here h is the Planck constant and the value is $h = 6.626*10^{-34} J \cdot s$

m is the mass of the electron with values $m = 9.1*10^{-31} \ kg$

$v = \frac{23 * 6.626*10^{-34} }{2\pi * 9.1 *10^{-31} * 3.05*10^{-8} }$

$v = 87377.95 \ m/s$

3 0

3 years ago

Circuit A in a house has a voltage of 208 V and is limited by a 40.0-A circuit breaker. Circuit B is at 120.0 V and has a 20.0-A

Setler79 [48]

Given Information:

Voltage of circuit A = Va = 208 Volts

Current of circuit A = Ia = 40 Amps

Voltage of circuit B = Vb = 120 Volts

Current of circuit B = Ib = 20 Amps

Required Information:

Ratio of power = Pa/Pb = ?

Answer:

Ratio of power = Pa/Pb = 52/15

Explanation:

Power can be calculated using Ohm's law

P = VI

Where V is the voltage and I is the current flowing in the circuit.

The power delivered by circuit A is

Pa = Va*Ia

Pa = 208*40

Pa = 8320 Watts

The power delivered by circuit B is

Pb = Vb*Ib

Pb = 120*20

Pb = 2400 Watts

Therefore, the ratio of the maximum power delivered by circuit A to that delivered by circuit B is

Pa/Pb = 8320/2400

Pa/Pb = 52/15

4 0

3 years ago

A hiker is at the bottom of a canyon facing the canyon wall closest to her. She is 280.5 meters from the wall and the sound of h

ValentinkaMS [17]

Answer:

4.80 seconds

Explanation:

The velocity of sound is obtained from;

V= 2d/t

Where;

V= velocity of sound = 329.2 ms-1

d= distance from the wall = 790.5 m

t= time = the unknown

t= 2d/V

t= 2 × 790.5/ 329.2

t= 4.80 seconds

8 0

3 years ago

A(n) 83 kg fisherman jumps from a dock into a 139 kg rowboat at rest on the West side of the dock. If the velocity of the fisher

Anna71 [15]

here we can say that there is no external force on fisherman and dock

so here we will use momentum conservation theory

As per momentum conservation

initial momentum of fisherman + boat = final momentum of fisherman + boat

$m_1v_{1i} + m_2v_{2i} = m_1v_{1f} + m_2v_{2f}$

now we will have

$83(3.1) + 139(0) = 83 v + 139 v$

$257.3 = 222v$

$v = 1.16 m/s$

so the speed of boat and fisherman will be 1.16 m/s

3 0

3 years ago

A mass-spring system has k = 56.8 N/m and m = 0.46 kg.

andriy [413]

Answer:

A. $\omega=11.1121\ rad.s^{-1}$

B. $f=1.7685\ Hz$

C. $T=0.5654\ s$

Explanation:

Given:

spring constant, $k=56.8\ N.m^{-1}$

mass attached, $m=0.46\ kg$

for a spring-mass system the frequency is given as:

$\omega=\sqrt{\frac{k}{m} }$

$\omega=\sqrt{\frac{56.8}{0.46}}$

$\omega=11.1121\ rad.s^{-1}$

frequency is given as:

$f=\frac{\omega}{2\pi}$

$f=\frac{11.1121}{2\pi}$

$f=1.7685\ Hz$

Time period of a simple harmonic motion is given as:

$T=\frac{1}{f}$

$T=0.5654\ s$

7 0

3 years ago