Answer:
a) 20 minutes
b) 36 km/h
c) 33.67 km
d) continuous driving without any stationary phases.
Step-by-step explanation:
by the way, speed is specified in distance per time unit. in your example as km/h. and that is how your write this.
not km/h¯¹. that would be wrong, as that would actually be km×h. but you can write e.g. km×h¯¹. that is the same as km/h.
between minutes 5 and 25 there is no progress in distance. so, for these 20 minutes the bus was stationary.
in the first 5 minutes the bus drove 7-4=3 km.
so, in 5 minutes 3 km. to determine the speed we need to calculate up to see, how many km would be have driven in a full hour (60 minutes). the same factor for the time has then to be applied also to the distance to keep the ratio unchanged.
5 × x = 60
x = 12
3 × 12 = 36
so, the speed in these first 5 minutes was 3 km/5 min.
or then in km/h : 36 km/h
between the minutes 25 and 45 the bus drove with a speed of 80km/h.
and the starting point there was at 7 km.
so, the bus drove s-7 km in 20 minutes.
as before, let's first find the scaling factor to deal with a full hour instead of only 20 minutes.
20 × x = 60
x = 3
as before : distance × scaling factor = distance for km/h
(s-7) × 3 = 80
3s - 21 = 80
3s = 101
s = 33.666666666... km
Answer:
28.26 
Step-by-step explanation:
The area of the quarter circle is the area of the circle / 4. Thus, the area is
=
= 28.26 square centimeters
Answer:
The plane's distance from the radar station will increase about 8 miles per minute when it is 5 miles away from it.
Step-by-step explanation:
When the plane passes over the radar station, the current distance is the altitude h = 2. Then it moves b horizontally so that the distance to the station is 5. We can form a rectangle triangle using b, h and the hypotenuse 5. Therefore, b should satisfy
h²+b² = 5², since h = 2, h² = 4, as a result
b² = 25-4 = 21, thus
b = √21.
Since it moved √21 mi, then the time passed is √21/540 = 0.008466 hours, which is 0.51 minutes. Note that in 1 minute, the plane makes 540/60 = 9 miles.
The distance between the plane and the radar station after x minutes from the moment that the plane passes over it is given by the function

We have to compute the derivate of f in x = 0.51. The derivate of f is given by

also,

The plane's distance from the station will increase about 8 miles per minute.
Answer:
d = 483.56 inches
Step-by-step explanation:
We have,
Radius of a bicycle tire is 11 inches. It is required to find the distance traveled by the distance covered by the tire when it makes 7 revolutions. One revolution means the circumference of circle. So,

In 7 revolution, it will cover a distance of 7C i.e.

So, the tire will cover a distance of 483.56 inches in 7 revolutions