Explanation:
average speed = total distance travelled / total time travelled
time to travel the first 6km: 6 / 50 = 3/25 (h)
time to travel the next 6km: 6 / 90 = 1/15 (h)
[I think there's problem in the question 'cause 900km/h sounds impossible for normal person to travel in normal condition]
The total time: 3/25 + 1/15 = 14/75 (h)
Average speed over the 12 km drive will be:

Answer:Force is to the right
Explanation: because the right side has 75N compared to the 25N on the left.
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the answer is spiral galaxies
Answer:
The length of the stick is 0.28 m.
The time the stick take to move is 0.97 ns.
Explanation:
Given that,
Relative speed of stick v= 0.96 c
Speed of light 
Proper length of stick = 1 m
We need to calculate the length of the stick
Using formula of length

Put the value into the formula



We need to calculate the time the stick take to move
Using formula of time

Put the value into the formula



Hence, The length of the stick is 0.28 m.
The time the stick take to move is 0.97 ns.