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Mariana [72]
2 years ago
14

a radioactive element has a half-life of 30 days. calculate the mass of the element that remains after 20 days if 100g of the el

ement decays. Also, calculate the decay constant.
Physics
1 answer:
patriot [66]2 years ago
4 0

Explanation:

the answer is in the image above

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How much energy is required to raise the temperature of 50.0 grams of water 10.0 degree C? (Explain yourself answer in joules!)
maria [59]

The amount of energy needed is 2093 J

Explanation:

The amount of energy needed to increase the temperature of a substance by \Delta T is given by the equation

Q=mC\Delta T

where

m is the mass of the substance

C is its specific heat capacity

\Delta T is the increase in temperature

For the water in this problem, we have

m = 50.0 g = 0.050 kg

C=4186 J/g^{\circ}C (specific heat capacity of water)

\Delta T=10.0^{\circ}C

Therefore, the amount of energy needed is

Q=(0.050)(4186)(10)=2093 J

Learn more about specific heat capacity:

brainly.com/question/3032746

brainly.com/question/4759369

#LearnwithBrainly

4 0
3 years ago
Is the acceleration due to gravity in projectile motion always negative? please explain
umka21 [38]
Before you start working on any motion problem, YOU decide which direction you're going to call 'positive'. Everybody almost always calls UP positive, and the acceleration of gravity points down, so it winds up negative. But you could just as well call DOWN the positive direction. Then, the cannonball is fired with a negative vertical speed, and the acceleration of gravity eventually robs all of its negative speed, and makes it start falling in the positive direction. The whole thing is your choice.
3 0
3 years ago
If you hold a bar magnet in each hand and bring your hands together, will the force be attractive or repulsive if the magnets ar
NemiM [27]

Answer:

<u><em>Part A:</em></u>

They will repel each other because same poles repel each other.

<u><em>Part B)</em></u>

They will attract each other because different poles attract each other..

5 0
3 years ago
A thin layer of oil of refractive index 1.22 is spread on the surface of water (n = 1.33), If the thickness of the oil is 275 nm
ANTONII [103]

Answer:

6.71×10⁻⁷ m

Explanation:

Using thin film constructive interference formula as:

<u>2×n×t = m×λ</u>

Where,

n is the refractive index of the refracted surface

t is the thickness of the surface

λ is the wavelength

If m =1

Then,

2×n×t = λ

Given that refractive index pf the oil is 1.22

Thickness of the oil = 275 nm

Also, 1 nm = 10⁻⁹ m

Thickness = 275×10⁻⁹ m

So,

Wavelength is :

<u>λ= 2×n×t = 2× 1.22 × 275×10⁻⁹ m = 6.71×10⁻⁷ m</u>

8 0
3 years ago
Mark and Leo are doing a experiment to see if rocks float. Leo uses a sedimentary rock. Does it float? Why or why not?
mrs_skeptik [129]
No because the rock isn't hollow it is hard from the inside out so it sinks because of its mass
8 0
3 years ago
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