12. The answer would be C. 1.50 s. This is because if you divide 60 by 40, you will get 1.5.
13. For this one I'm not sure, but what I can tell you is that the heavier something is the faster it will sink, the lighter it is, it will float.
A. Base , salt , water,acid
Answer: Kinetic frictional force = 23.76N
Explanation: Please see the attachments below
hi <3
i believe i explained this answer properly in my last answer but it would be 4kg and 2400m as these are the SI units for these values.
hope this helps :)