Answer:
If you are looking for past papers you can search that up and you will find plenty of resources that will help you out.
A is the answer to what your asking
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:

So velocity=displacement/time and force=mass*acceleration. Both objects have the same acceleration because the amount of time doesn’t play a role in the equation. Momentum equation is p=mv so only the mass and overall velocity matter. Therefore, the answer is c because time is not a variable
50N.
The magnitude of the reaction to any force is equal to the magnitude of the first force. (See Newton #3.)