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2 years ago

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Determine the amount of time for polonium-210 to decay to one fourth its original quantity. The half-life of polonium-210 is 138

days. Explain.

1 answer:

Tju [1.3M]2 years ago

5 0

Answer:

276 days

Explanation:

1/4 th of the original means <u><em>2 half lives</em></u>

1 half life = 138 days

So,

2 half lives = 276 days

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Two compact sources of sound oscillate in phase with a frequency of 100 Hz. At a point 5.00m from one source and 5.85 m from the

antoniya [11.8K]

Answer:

(a)1.557 radian (b) 1.424 A

Explanation:

Frequency of oscillation of sound = 100 Hz

$\Delta r=5.85-5=0.85m$

(a)The phase difference is given by $\frac{2\pi \Delta r}{λ}$ where v is the velocity of sound in air

So phase difference $\frac{2\pi \Delta rf}{v}$ as $\lambda =\frac{v}{f}$

So phase difference $=\frac{2\times 3.14\times 0.85\times 100}{343}=1.557radian$

(b) The resultant amplitude is given by $2Acos\frac{\Phi }{2}=2\times A\times cos\frac{1.557}{2}=1.424A$

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2 years ago

What is the difference between polarized light and unpolarized light?

vekshin1

Unpolarized light has light waves that are oriented in all directions while polarized light has all the light waves oscillating in one direction. An example for unpolarized is the Sun, or any other simple type of light.

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a 25 newton force applied on an object moves it 50 meters. the angle between the force and displacement is 40.0°. what is the va

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Work = force × distance × cos(angle)

work = (25)(50)(cos (40))

work = 957.56 Joules

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What is the average speed in mph for a car that travels for 5 hours and 20 minutes?

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Explanation:

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Read 2 more answers

A person kicks a ball, giving it an initial velocity of 20.0 m/s up a wooden ramp. When the ball reaches the top, it becomes air

Alex Ar [27]

Answer:

(a) Height is 4.47 m

(b) Height is 4.37 m

Solution:

As per the question:

Initial velocity of teh ball, $v_{o} = 20.0 m/s$

Angle made by the ramp, $\theta = 22.0^{\circ}$

Distance traveled by the ball on the ramp, d = 5.00 m

Now,

(a) At any point on the projectile before attaining maximum height, the velocity can be given by the eqn-3 of motion:

$v^{2} = v_{o}^{2} - 2gH$

where

H = $dsin22^{\circ} = 5sin22^{\circ}$

g = $9.8 m/s^{2}$

$v^{2} = 20^{2} - 2\times 9.8\times 5sin22^{\circ}$

$v = \sqrt{400 - 19.6\times 5sin22^{\circ}}$ = 19.06 m/s

Now, maximum height attained is given by:

$h = \frac{(vsin\theta)^{2}}{2g}$

$h = \frac{(19sin(22^{\circ}))^{2}}{2\times 9.8} = 2.60 m$

Height from the ground = $5sin22^{circ} + 2.86 = 1.87 + 2.60 = 4.47m$

(b) now, considering the coefficient of friction bhetween ramp and the ball, $\mu = 0.150$ :

velocity can be given by the eqn-3 of motion:

$v^{2} = v_{o}^{2} - 2gH - \mu gd$

$v^{2} = 20^{2} - 2\times 9.8\times 5sin22^{\circ} - 0.150\times 9.8\times 5$

$v = \sqrt{400 - 19.6\times 5sin22^{\circ} - 0.150\times 9.8\times 5}$ = 18.7 m/s

Now, maximum height attained is given by:

$h = \frac{(vsin\theta)^{2}}{2g}$

$h = \frac{(18.7sin(22^{\circ}))^{2}}{2\times 9.8} = 2.50 m$

Height from the ground = $5sin22^{circ} + 2.86 = 1.87 + 2.50 = 4.37 m$

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2 years ago