Answer:
2.28 s
Explanation:
Let g = 9.8 m/s2 and neglect air resistance. The box of sand with an initial velocity of 4.2m/s in free fall would yield the following equation of motion



t = 2.28 or t = -3.14
Since t can only be positive we will pick t = 2.28
s
The first one is C!
I hope the answer helped! please mark brainliest and vote 5 stars! >:)
After they are all used up they can’t be renewed or used anymore.
4095km
Explanation:
Given parameters:
Starting time = 7 o'clock
Stopping time = 11hrs 30min
Speed = 910km/hr
Unknown:
Distance covered = ?
Solution:
Speed is the rate of change of distance with time.
It is a scalar quantity that is with respect with magnitude but no direction.
Speed = 
Distance = Speed x time
Time taken = time between 11hrs 30min and 7 o'clock = 4.5hrs
Input the parameters:
Distance = 910km/hr x 4.5hrs = 4095km
learn more:
Speed brainly.com/question/10048445
#learnwithBrainly