Answer:
18 minutes
Step-by-step explanation:
A = A₀ (½)^(t / T)
where A is the final amount,
A₀ is the initial amount,
t is the time,
and T is the half life.
A = 140 when t = 10. Solve for the half life:
140 = 700 (½)^(10 / T)
0.2 = ½^(10 / T)
log 0.2 = (10 / T) log 0.5
10 / T = 2.32
T = 4.31
When A = 40, t is:
40 = 700 (½)^(t / 4.31)
0.057 = ½^(t / 4.31)
log 0.057 = (t / 4.31) log 0.5
t / 4.31 = 4.13
t = 17.8
Rounded to the nearest whole number, it takes 18 minutes.
Answer:
<h2>400</h2>
Step-by-step explanation:

A cardboard box rests on the floor of an elevator. The box has a mass m = 3.75 kg and the elevator has an upward acceleration of a
Part a. Select the Free Body Diagram for the system
Part b. Write an expression for the sum of the forces actinv on the box in the y direcion, given that up is the positive y direction. Your answer should be in terms of FN, m, g.
Part c. Write an expression for the normal force FN, that the block experiences in terms of the elevator's accelaration, the block's mass and the accelaration of gravity
Part d. If the elevator's accelaration has a magnitude of g in the downward direction, what would the normal force FN1 be in Newtons? (Numerical value)
Part e. If the elevator's accelaration had a magnitude of g in the upward direction, what would the normal force FN2 ve in Newtons? (Numerical value)
3) It's basically asking how many 7 ounce servings can be made out of a 64 ounce container. Divide 64 by 7 and you will get a decimal but their asking for full servings so round down to the closest whole number