Answer:OD. a hummingbird moving at 25 mph
Explanation:
The average speed of the bus from Lansing to Detroit is

while the average speed of the bus from Detroit to Lansing is

The distance covered by the bus in the two trips is the same (the distance between the two cities), therefore, the average speed of the round trip can be calculated as the mean of the two speeds:
Answer: 25.38 m/s
Explanation:
We have a straight line where the car travels a total distance
, which is divided into two segments
:
(1)
Where 
On the other hand, we know speed is defined as:
(2)
Where
is the time, which can be isolated from (2):
(3)
Now, for the first segment
the car has a speed
, using equation (3):
(4)
(5)
(6) This is the time it takes to travel the first segment
For the second segment
the car has a speed
, hence:
(7)
(8)
(9) This is the time it takes to travel the secons segment
Having these values we can calculate the car's average speed
:
(10)
(11)
Finally:
Answer:
The total displacement is 102 km
north of east.
Explanation:
We can treat this problem as a trigonometric one, so we need to calculate the total displacement on the north and east.

and

The total displacement is given by:

with an agle of:

For this case, what we must do is to rewrite these measurements in the same unit in order to compare them.
By writing the measurements in meters we have:



Therefore, physically the correct measure is:

Answer:
the length of a student's textbook most likely is:
30 centimeters