
you're given all those values, h,k and r, so just plug them in
Answer:
it is C
Step-by-step explanation:
why because look at the numbers and youll understand
Answer:
the remaining mass of unobtanium -41 after a 5 seconds, 10 seconds, 15 seconds and 20 seconds is 24 gr, 12 gr , 5.33 gr and 3 gr respectively
Step-by-step explanation:
the equation that governs the remaining mass m of unobtanium -41 after a time t is
m=m₀*2^(-t/T) , where t is in seconds ,m₀ represents initial mass and T=half-life
Therefore
a) for t=5 s
m=48 gr*2^(-t/5 s) = 48 gr*2^(-5 s/5 s) = 48 gr/2 = 24 gr
b) for t=10 s
m=48 gr*2^(-t/5 s) = 48 gr*2^(-10 s/5 s) = 48 gr/4 = 12 gr
b) for t=15 s
m=48 gr*2^(-t/5 s) = 48 gr*2^(-15 s/5 s) = 48 gr/9 = 5.33 gr
b) for t=20 s
m=48 gr*2^(-t/5 s) = 48 gr*2^(-20 s/5 s) = 48 gr/16 = 3 gr
thus the remaining mass of unobtanium -41 after a 5 seconds, 10 seconds, 15 seconds and 20 seconds is 24 gr, 12 gr , 5.33 gr and 3 gr respectively
She gave $14 to her sister.
Explanation:
The word "of" in fraction word problems USUALLY signals for you to multiply. So, we want to find 2/5 of 35, so we multiply 2/5 x 35. That gives us 14, therefore she gave $14 to her sister
One piece will be length x and the other piece will be 20 cm longer, so it will be x + 20 cm long.
Added together the length of these two boards will equal 86 cm. So you can write an equation:
x + (x + 20) = 86
Remove the parentheses and add the two x's together to get:
2x + 20 = 86
Subtract 20 from both sides:
2x = 66
Divide both sides by 2 and you have:
x = 33
The short piece is 33 cm and the other piece is 20 cm longer or 33 + 20 = 53 cm.