Answer:
The mass of Uranium present in a 1.2mg sample is 
Explanation:
The ration between Uranium mass and total sample mass is:
For a sample of mass 1.2 mg, the amount of uranium is:

Answer:
In the 1980s, astronomers turned to multiverse theory to explain the “luckily small” amount of dark energy in our universe. According to cosmologist's theories, this small amount of dark energy appeared to enable our universe to host life, while most universes in the multiverse couldn't.
Explanation:
As per the question Bob drops the bag full with feathers from the top of the building.
The mass of the bag(m)= 1.0 lb
Let the air resistance is neglected.As the bag is under free fall ,hence the only force that acts on the bag is the force of gravity which is in vertical downward direction.
Here the acceleration produced on bag due to the free fall will be nothing else except the acceleration due to gravity i.e g =9.8 m/s^2
Here we are asked to calculate the distance travelled by the bag at the instant 1.5 s
Hence time t= 1.5 s
From equation of kinematics we know that -
S=ut + 0.5at^2 [ here S is the distance travelled]
For motion under free fall initial velocity (u)=0.
Hence S= 0×1.5+{0.5×(-9.8)×(1.5)^2}
⇒ -S =0-11.025 m
⇒ S= 11.025 m
=11 m
Here the negative sign is taken only due to the vertical downward motion of the body .we may take is positive depending on our frame of reference .
Hence the correct option is B.
Answer:

Explanation:
MA ( Mechanical Advantage ) is always less than VR ( Velocity Ratio ) because <u>MA</u><u> </u><u>is</u><u> </u><u>reduced</u><u> </u><u>by</u><u> </u><u>friction</u><u> </u><u>but</u><u> </u><u>VR</u><u> </u><u>is</u><u> </u><u>not</u><u> </u><u>affected</u><u> </u><u>by</u><u> </u><u>friction</u><u>.</u>
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