Answer:
5 weeks and 5 days is required to empty the lake
Explanation:
Officials begin the remove water from a full man made lake
The lake can be emptied in 4 weeks
= -1/4
A river can fill the lake up in 15 weeks
= 1/15
Let t represent the number of weeks that is required to empty the lake
= -1/t
Therefore the number of weeks it takes to empty the lake can be calculated as follows
-1/t= -1/4 + 1/15
-1/t= -11/60
Cross multiply
-11×t= -1×60
-11t= -60
t = 60/11
t= 5 5/11
Hence it takes 5 weeks and 5 days to empty the lake
<span>Density can be calculated and found by dividing the sample's mass by its volume. D=m/v</span>
1)Food is crushed and ground in the mouth by teeth
2)Chewed food is pushed into the pharynx
3)Food enters the esophagus
4)Food passes through a valve and into the stomach
5)Food is broken down by pancreatic enzymes and absorbed by the small intestine
6)Undigested material is pushed into the large intestine
7)Waste material is compressed in the rectum and eliminated through the anus
Convex Lenses are used to focus light and form a image. They are transparent.
They are one type of lenses. Different type of lenses are used to focus light differently. The basic lenses are concave and convex. Convex lenses converge light falling on it whereas concave lenses diverge light falling on it.