Answer:
The height of the pile is increasing at the rate of 
Step-by-step explanation:
Given that :
Gravel is being dumped from a conveyor belt at a rate of 20 ft³ /min
i.e 
we know that radius r is always twice the diameter d
i.e d = 2r
Given that :
the shape of a cone whose base diameter and height are always equal.
then d = h = 2r
h = 2r
r = h/2
The volume of a cone can be given by the formula:




Taking the differentiation of volume V with respect to time t; we have:


we know that:

So;we have:



The height of the pile is increasing at the rate of 
Answer:
10 mph
Step-by-step explanation:
speed of boat in still water = x
speed of current = 5
speed of boat with current (downstream) = x + 5
speed of boat against current (upstream) = x - 5
distance downstream = 9
distance upstream = 3
time = t
speed = distance/time
distance = speed × time
downstream:
9 = (x + 5)t
upstream:
3 = (x - 5)t
9 = xt + 5t
3 = xt - 5t
9 = xt + 5t
-3 = -xt + 5t
-----------------
6 = 10t
t = 0.6
9 = (x + 5)0.6
15 = x + 5
x = 10
Answer:
5/12 barrel/hour
Step-by-step explanation:
Type this as a fraction:
(1/6) barrel
--------------------
(2/5) hours
Division by 2/5 is equivalent to multiplication by 5/2:
1 5
--- barrel * -------------- = 5/12 barrel/hour
6 2 hours
Alternatively, this problem could be done using decimal fractions:
0.1667 barrel
-------------------- = 0.416666 barrel/hour = 5/12 barrel/hour
0.4 hours
Answer: 7.867 x 10^8
Step-by-step explanation:
(the “^8” is an exponent of 8)
Answer:
20 minutes
Step-by-step explanation:
The mean, or average of a data set can be found by adding all the values together, and dividing by the number of values.
The data set is: 20 minutes, 22 minutes and 18 minutes
1. Add the values together
Add all the numbers in the set together.
Data set: 20, 22, 18
Add them: 20+22+18
60
2. Divide by the number of values
Count how many numbers are in the set.
In this set, there are 3 numbers.
Divide 60 by 3
60/3 =20
20 minutes
His mean time is 20 minutes.