This is an easy half-life calculation because it involves an exact integer of half-lives. 1,104 days is precisely 8 half-lives. After each half-life, one half of the original remains.
So, after 8 half-lives you will have 1 / 2^8 of the original material left.
So we start with 30 grams and 1 / 2^8 =
<span>
<span>
<span>
0.00390625</span></span></span>.
We are therefore left with (30 *
<span>
<span>
<span>
0.00390625) or </span></span></span>
<span>
<span>
<span>
0.1171875 grams of the original 30 grams of polonium.
</span>
</span>
</span>
Answer:
She should aim 6 feet down the wall
Explanation:
The diagram attached sketches the situtation.
Since the angle with which the ball hits the wall is the same with which it bounces, angle β is the same for the two shown triangles.
Then, since both are right triangles, then all the angles are congruent and the triangles are similar. Hence, you can equal the ratios of the sides, to make an equation:
x/4 = y/2 ⇒ x = 2y
You have other equation:
x+ y = 18
Substitute
2y + y = 18
3y = 18
y = 18/3
y = 6 ← this is the distance down the wall where the ball should hit
x = 2(6) = 12
Then, she should aim 6 feet down the wall.
Answer:
210 ft^2
Step-by-step explanation:
The area of a triangle is
A = 1/2 bh where b is the base and h is the height
Since this is a right triangle the base is 20 ft and the heigth is 21 ft
A = 1/2 ( 20) * 21
210 ft^2
Answer:
(c) H0 should be rejected
Step-by-step explanation:
Null hypothesis (H0): population mean is equal to 5
Alternate hypothesis (Ha): population mean is greater than 5
Z = (sample mean - population mean) ÷ (sd/√n)
sample mean = 5.3, population mean = 5, sd = 1, n = 500
Z = (5.3 - 5) ÷ (1/√500) = 0.3 ÷ 0.045 = 6.67
Using the normal distribution table, for a one tailed test at 0.01 significance level, the critical value is 2.326
Conclusion:
Since 6.67 is greater than 2.326, reject the null hypothesis (H0)
Answer:
The salary after all the increment = $62899.0879
Step-by-step explanation:
It is given that starting annual salary = $55183
There is given that there are there are three time increment of 0.6 %
So salary after 0.6% increment of 3 times = 
= $56182.2656
After that there is other increment of 1.9 % that is 6 times
So salary after this increment = 
So the salary after all the increment = $62899.0879
