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Free_Kalibri [48]
3 years ago
12

alayn h uderstands the half life of a certain substance is 90days. how long would it take for 80lbs of her substance to be reduc

ed to 20lbs
Physics
1 answer:
yan [13]3 years ago
7 0

Answer:

135 days...............

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Thinking about an analogue clock, calculate the angular displacement in revolutions, radians and degrees for the following: • A
Inessa [10]

Answer:

1.047 rad

Explanation:

A secondhand makes a complete revolution (360 degrees) in 60 seconds, so it displaces 6 degrees for every second of elapsed time (360/60 = 6).

And in 10 seconds, it will make a displacement of 10 degrees (6 * 10 = 60).

Finally converting the result into Radians by multiplication with π/180.

5 0
2 years ago
A sound wave from a siren has an intensity of 111.2 W/m2 at a certain point, and a second sound wave from a nearby ambulance has
Kazeer [188]

Answer:

The intensity level of the sound wave due to the ambulance is 153.5 dB.

Explanation:

The intensity level of the sound wave due to the ambulance can be calculated using the following equation:

\beta = 10log(\frac{I}{I_{0}})

<u>Where</u>:

I: is the intensity of the sound wave from a siren = 111.2 W/m²      

I₀: is the reference intensity = 1.0x10⁻¹² W/m²

\beta = 10log(\frac{111.2 W/m^{2}}{1.0 \cdot 10^{-12} W/m^{2}}) = 140.5 dB

Now, since the second sound wave from a nearby ambulance has an intensity level 13 dB we have:

I_{a} = 13 dB + 140.5 dB = 153.5 dB

Therefore, the intensity level of the sound wave due to the ambulance is 153.5 dB.

I hope it helps you!                      

5 0
3 years ago
Atoms with the same atomic number but different atomic mass are called
Alexxx [7]
<span>Atoms with the same atomic number but different atomic mass are called:

<span>Isotopes</span>
</span>
4 0
3 years ago
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Explain about ohm's law.​
belka [17]

Answer:

Statement:

The electric current passing through a conductor is directly proportional to the potential difference across its ends provided temperature and other physical conditions remain constant.

Explanation:

Current is directly proportional to voltage loss through a resistor. That is, if the current doubles, then so does the voltage. To make a current flow through a resistance there must be a voltage across that resistance. Ohm's Law shows the relationship between the voltage (V), current (I) and resistance (R).

V∝I or I∝V⇒V=IR.

4 0
3 years ago
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A stone is thrown from a cliff and lands in the sea. Air resistance is negligible. Which statement is correct whilst the stone i
erik [133]
Since the stone is travelling, the displacement cannot be constant. This leaves the last 2 choices as possibilities. Now consider the acceleration that can act on the stone. Acceleration due to gravity is the only one. That means the horizontal component of the stone has to be constant since there is no acceleration in the horizontal direction.
4 0
3 years ago
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