Kinetic Energy= 0.5 times velocity squared times mass
So KE= 0.5times 150 times 40 squared
(Use a calculator)
And don't forget units
Answer:
The mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
Explanation:
We are given that
Aqueous solution that contains 22.9% NaOH by mass means
22.9 g NaOH in 100 g solution.
Mass of NaOH(WB)=22.9 g
Mass of water =100-22.9=77.1
Na=23
O=16
H=1.01
Molar mass of NaOH(MB)=23+16+1.01=40.01
Number of moles =
Using the formula
Number of moles of NaOH

Molar mass of water=16+2(1.01)=18.02g
Number of moles of water

Now, mole fraction of NaOH
=

=0.882
Hence, the mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
Answer:-
As we can see from the graphical data,
The distance covered by all the four runners is the same 5 km.
Among the four athletes, Athlete P covers the distance in under three hours.
It is the minimum time taken among the four athletes.
Thus Athlete P covers the 5 km distance in the minimum amount of time.
We know that speed = 
Since time taken for P is minimum, his speed is the maximum. P ran the fastest.
Time taken by Q = 4.5 hours.
Speed of Q = 
= 
= 1.1 km/ hr
Time taken by R = 6 hours.
Speed of R = 
= 
= 0.8 km/ hr
Molar mass Li2CO3 = 73.89 g/mol
Molar mass Li = 6.94g/mol Li = 6.94*2 = 13.88g
% LI = 13.88/73.89*100 = 18.78% perfectly correct.