Answer:
He will take 60 seconds to move from one end of the sidewalk to other.
Step-by-step explanation:
Given:
A person on a moving sidewalk,
21 feet in 7 seconds
Then 180 feet
To Find:
Total time =?
Solution:
Speed:
Speed is defined as the rate of distance covered in per unit time.
It is given as
Substituting the given values we get
Now, With this speed if he walk 180 feet then the time is
Substituting Speed and Distance we get
He will take 60 seconds to move from one end of the sidewalk to other.
Answer:
81 + 6 + 1 = 88 if that's your question
Step-by-step explanation:
<span>The answer is 9,990 years. Using the exponential decay question, we can figure out how long it will take Plutonium-240 to decay from 27 grams to 9 grams. Setting the equation up looks like this, 9 = 27 e^ (-0.00011 t). From this you get, 0.333333 = e ^(-0.00011 t). Next, you simplify by dividing both sides by the natural log, -1.0986 = -0.00011 t. Finally, you solve by dividing both sides by -0.00011, giving 9,987 years for t, rounded up to 9,990 years.</span>
Step-by-step explanation:
Watch all steps in picture
