The total momentum before and after the collision must be conserved.
The total momentum before the collision is:

where m1 and m2 are the masses of the two players, and

and

their initial velocities. Both are considered with positive sign, because the two players are running toward the same direction.
The final momentum is instead

because now the two players are moving together with a total mass of (m1+m2) and final speed vf.
By requiring that the momentum is conserved

we can calculate vf, the post-collision speed:


and the direction is the same as the direction of the players before the collision.
Answer:
m =8.81*10^{-6}grams
time t = 52.8 year
Explanation:
GIVEN DATA:
the half life of the CO-60 is, T_1/2 = 5.27 years = 1.663 e+8 s
activity dN/dt = 1 mCi = 3.7 X 10^7 decay/s
activity , 


= ( 3.7 X 10^7 )(1.663*10^8 ) / ln2
= 8.877*10^{16}
Number of moles:
n = N/NA = 8.877*10^{16} / 6.022X10^23 = 1.474*10^{-7} mol
mass of the CO-60 is,
m = n*M = [1.474*10^{-7} mol]*[59.93 grams /mol] = 8.81*10^{-6}grams
-----------------------------------------------------------------------------------------
time t = -[T1/2 / ln2]*ln[N/N0]
= - [5.3 years / ln2]*ln[1x10-6/1x10-3]
= 52.8 year
Answer:
Her measurements will be more accurate if she uses a cloth tape
measure instead of a ruler.
Explanation: (apex)
Answer:
4m/s2
Explanation:
acceleration=v-u/t...v=12m/s,u=0m/s,t=3sec
a=12-0/3
=4m/s2
if there were no invention of machines then life would have been more difficult and simple works could be hard to do. Even now we are using our phones, sitting in a AC room interacting to eachother from different places. without the invention of machines simple things like transportation would have been difficult. There would be horses and donkey for the transportation. There would be no electricity,no internet, no transportation, not even c computers or mobile etc. The market for business will be smaller, the knowledge and news about world would be less.
so the problem would have been bigger than we can imagine. But one thing is that nature could survive lot more compared to what we have done till now by destroying nature.