I would say A Because it weighs more than the water
Plants and animals need nitrogen in order to make proteins. Proteins are essential compounds for healthy growth and fully functioning organisms.
Answer:
a) The perimeter of the rectangle is 29.4 centimeters.
b) The uncertainty in its perimeter is 0.8 centimeters.
Explanation:
a) From Geometry we remember that the perimeter of the rectangle (
), measured in centimeters, is represented by the following formula:
(1)
Where:
- Width, measured in centimeters.
- Length, measured in centimeters.
If we know that 
and 
, then the perimeter of the rectangle is:
The perimeter of the rectangle is 29.4 centimeters.
b) The uncertainty of the perimeter (
), measured in centimeters, is estimated by differences. That is:
(2)
Where:
- Uncertainty in width, measured in centimeters.
- Uncertainty in length, measured in centimeters.
If we know that 
and 
, then the uncertainty in perimeter is:
The uncertainty in its perimeter is 0.8 centimeters.
Answer:
The resultant velocity of the boat = 5 m/s
The time it will take for the man to reach the other shore of the river = 25 s
Explanation:
width of river = 100 m
The velocity of the motorboat = 4 m/s eastward
The velocity of the water current = 3 m/s northward
The resultant velocity of the boat is:
R^2 = 4^2 + 3^2
= √ (4^2) + (3^2)
= √16 + 9
=√25
= 5 m/s
The time it will take for the man to reach the other shore of the river is:
d = 100 m
v = 4 m/s
t = d / v
t = 100 / 4
t = 25 s
