28/80 and then you simplify it by dividing the numerator and denominator by 4 and you get 7/20.
B. 7/20 is the correct answer
The answer is 4 m/s.
In the first 5 seconds, a body travelled 10 meters. In the first 10 seconds of the travel, the body travelled a total of 30 meters, which means that in the last 5 seconds, it travelled 20 meters (30m + 10m).
The relation of speed (v), distance (d), and time (t) can be expressed as:
v = d/t
We need to calculate the speed of the second 5 seconds of the travel:
d = 20 m (total 30 meters - first 10 meters)
t = 5 s (time from t = 5 seconds to t = 10 seconds)
Thus:
v = 20m / 5s = 4 m/s
Step-by-step explanation:
2(10)+2(x+4)
20 + 2x + 8
20 +8 +2x
28+2x
The formula of the volume of a cylinder:
We have:
and
substitute:
Answer: The area of a base of the cylinder is equal 45 dm².
