Answer:
average speed is 60km/h
Explanation:
you sum up the speed attained in each distance covered and divide it by 2 to get your answer

Actually Welcome to the Concept of the Optical Devices.
Now basically here the devices that can spread light over apart are the CONCAVE LENS and Convex mirror.
so the Answer is
C. B and D
Answer:
12 mins
Explanation:
The distance covered is 5 km, divide this by 25 to get the fraction of an hour it takes. Doing this you get .2, times this by 60 min (1 hour) to get how many mins it takes
The answer to your question is C.
The period will be the same if the amplitude of the motion is increased to 2a
What is an Amplitude?
Amplitude refers to the maximum extent of a vibration or oscillation, measured from the position of equilibrium.
Here,
mass m is attached to the spring.
mass attached = m
time period = t
We know that,
The time period for the spring is calculated with the equation:

Where k is the spring constant
Now if the amplitude is doubled, it means that the distance from the equilibrium position to the displacement is doubled.
From the equation, we can say,
Time period of the spring is independent of the amplitude.
Hence,
Increasing the amplitude does not affect the period of the mass and spring system.
Learn more about time period here:
<u>brainly.com/question/13834772</u>
#SPJ4