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2 years ago

Answer the question below:

Physics

2 answers:

OLga [1]2 years ago

8 0

Answer:

Its D

Explanation:

Bezzdna [24]2 years ago

6 0

Answer:

D) the decay rates of radioactive uranium and lead

Explanation:

As we know that when she found the substance it must have some fixed ratio of radioactive uranium and Lead in that substance.

Here since Uranium is radioactive substance so it will continuously convert into Lead and this ratio will change with time

So here we can say that the ratio of radioactive uranium and lead will depend on its decay rate

now to find the age of the substance we can find the present ratio of lead and uranium in that substance and then compare it with freshly prepared substance.

so by the formula

we can find the age of the sample

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The concrete slab of a basement is 11 m long, 8 m wide, and 0.20 m thick. During the winter, temperatures are nominally 17°C and

mina [271]

Answer:

$\frac{dQ}{dt}= 4312 W$

Explanation:

As we know that base of the slab is given as

$A = 11 \times 8$

$A = 88 m^2$

now we know that rate of heat transfer is given as

$\frac{dQ}{dt} = \frac{kA}{x} (T_2 - T_1)$

here we know that

$k = 1.4 W/m k$

Also we have

$x =0.20$

$\frac{dQ}{dt} = \frac{1.4(88)}{0.20}(17 - 10)$

$\frac{dQ}{dt}= 4312 W$

7 0

3 years ago

Bambi the young dear was distracted Buy butterfly and jumped into the road in front of the two vehicles as shown in the diagram

bagirrra123 [75]

Speed of car A is given as

$v_a = 70 mph$

now we need to convert it into SI units

1 miles = 1609 m

1 hour = 3600 s

now we have

$v_a = 70 *\frac{1609}{3600} = 31.3 m/s$

now its distance from Bambi is given as

$d_a = 350 m$

time taken by it to hit the Bambi

$t = \frac{d}{v}$

$t = \frac{350}{31.3}$

$t = 11.2 s$

Now other car is moving at speed 50 mph

so its speed in SI unit will be

$v_b = 50* \frac{1609}{3600}$

$v_b = 22.35 m/s$

now its distance from Bambi is given as

$d_b = 590 feet$

as we know that 1 feet = 0.3048 m

$d_b = 590*0.3048 = 179.83 m$

now the time to hit the other car is

$t_2 = \frac{179.83}{22.35}$

$t_b = 8.05 s$

So Car B will hit the Bambi first

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3 years ago

10. According to Newton's First Lawy , if a box is pushed with no external resistance, what will the action of the box be ?

kati45 [8]

Explanation:

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4 0

3 years ago

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Give reason : the action and reaction do not lead to equilibrium ?

Natalija [7]

the action and reaction do not lead equilibrium if action and reaction force react on different objects

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3 years ago

By using fossils and matching layers rock layers can be correlated to eachother.

bija089 [108]

I think that the answer to that is true hope that helps

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3 years ago

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