Suppose you were to drop a stone down a well. A falling object obeys the equation s=16(t1)2 , where s is the distance fallen in feet and t is the time in seconds. Sound waves travel at a speed of about 1100 ft/sec, and the time it takes to travel a distance s is t2=s1100 . The total time it takes for you to hear the stone hit the water below equals the time it spent falling plus the time it takes the sound to reach your ear. What is the distance to the water's surface in the well if you hear the stone hit the water 4 seconds after dropping the stone?

228.64 ft

Step-by-step explanation:

Given that the total time, t it takes for you to hear the stone hit the water below equals the time it spent falling, t1 plus the time it takes the sound to reach your ear t2.

Given that t = 4s and t = t1 + t2.

So t1 + t2 = 4  (1)

Also s = 16(t1)² and t2 = s/1100

Thus t2 = 16(t1)²/1000

From (1), t2 = 4 - t1

So 4 - t1 = 0.016(t1)²

0.016(t1)² + t1 - 4 = 0

(t1)² + 62.5t1 - 250 = 0

Using the quadratic formula to find t1,

Since t1 cannot be negative, t1 = 3.78 s

So, s = 16(t1)²

= 16(3.78)²

= 16(14.29)

= 228.64 ft

The answer is in the image 

The total nom of  code that can be used is equal to 5+3 = 8

For every 8 cars there are 7 trucks

Therefore,

Cars:Truck=8:7

Answer is B)8:7

The solution is in the following image

F=ma

where F=force

m=mass

a=acceleration

Here,

F=4300

a=3.3m/s2

m=F/a

    =4300/3.3

    =1303.03kg

Approximately it is aqual to 1300kg

Salesperson will make 6% of 1800

=(6/100)*1800

=108

Salesperson will make $108 in $1800 sales

The solution is given in the image below

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.