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2 years ago

If 100.0 g of carbon-14 decays until only 25.0 g of carbon is left after 11 460 y, what is

Physics

1 answer:

pantera1 [17]2 years ago

3 0

Answer:

5730 yr

Explanation:

25 = 100 (1/2)^11460/x where x = half life

.25 = (1/2)^11460/x

log .25 / log.5 = 11460/x

x = 5730 yr

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The behaviors that light exhibits are reflection, refraction, diffraction, polarization, and dispersion. Answer

Molodets [167]

I believe the correct answer is false. The behaviors that light exhibits are reflection, refraction, diffraction but not polarization, and dispersion. Light<span> behaves as a wave - it undergoes reflection, refraction, and diffraction just like any wave would. Hope this answers the question.</span>

5 0

4 years ago

To drive a typical car at 40 mph on a level road for onehour requires about 3.2 × 107 J ofenergy. Suppose one tried to store thi

Ainat [17]

Answer:

$\omega=943\ rad/s$

Explanation:

Given that,

Speed of the car, v = 40 mph

Energy required, $E=3.2\times 10^7 J$

Radius of the flywheel, r = 0.6 m

Mass of flywheel, m = 400 kg

The kinetic energy of the disk is given by :

$E_k=\dfrac{1}{2}I\omega^2$

I is the moment of inertia of the disk, $I=\dfrac{mr^2}{2}$

$\omega^2=\dfrac{2E_k}{I}$

$\omega^2=\dfrac{2E_k}{\dfrac{mr^2}{2}}$

$\omega^2=\dfrac{2\times 3.2\times 10^7}{\dfrac{400\times (0.6)^2}{2}}$

$\omega=942.80\ rad/s$

$\omega=943\ rad/s$

So, the angular speed of the disk is 943 rad/s. Hence, this is the required solution.

8 0

3 years ago

if a body of mass 2kg travels with 2 m/s and other body of mass 2kg travels with 1m/s then find v1 and v2 in given statement

KIM [24]

Answer:

Your answer is here,

Explanation:

v1 = 4 kg m/s

v2 = 2 kg m/s

8 0

3 years ago

Two positive point charges of 12uc and Suc

GarryVolchara [31]

Answer:

54 N

Explanation:

We have two positive charges 12uC and 5 uC ,they are kept at a distance of 10cm.

We have a relation for force between two charges q1,q2 as

$F=\frac{kq1q2}{r^{2} }$

Value of k is $9*10^9$

On substituting the values into the equation we get,

$F=\frac{9*10^9*12*5}{10^9*10}\\\\ F=54N$

Hence the force between them is 54 N.

7 0

3 years ago

A 2.00 kg block hangs from a spring balance calibrated in Newtons that is attached to the ceiling of an elevator.(a) What does t

tresset_1 [31]

Answer:

Part a)

$Reading = 2.00 kg$

Part b)

$Reading = 2.00 kg$

Part c)

$Reading = 4.04 kg$

Part d)

from t = 0 to t = 4.9 s

so the reading of the scale will be same as that of weight of the block

Then its speed will reduce to zero in next 3.2 s

from t = 4.9 to t = 8.1 s

The reading of the scale will be less than the actual mass

Explanation:

Part a)

When elevator is ascending with constant speed then we will have

$F_{net} = 0$

$T - mg = 0$

$T = mg$

So it will read same as that of the mass

$Reading = 2.00 kg$

Part b)

When elevator is decending with constant speed then we will have

$F_{net} = 0$

$T - mg = 0$

$T = mg$

So it will read same as that of the mass

$Reading = 2.00 kg$

Part c)

When elevator is ascending with constant speed 39 m/s and acceleration 10 m/s/s then we will have

$F_{net} = ma$

$T - mg = ma$

$T = mg + ma$

Reading is given as

$Reading = \frac{mg + ma}{g}$

$Reading = 2.00\frac{9.81 + 10}{9.81}$

$Reading = 4.04 kg$

Part d)

Here the speed of the elevator is constant initially

from t = 0 to t = 4.9 s

so the reading of the scale will be same as that of weight of the block

Then its speed will reduce to zero in next 3.2 s

from t = 4.9 to t = 8.1 s

The reading of the scale will be less than the actual mass

3 0

3 years ago