Answer:
when work is done on the system or heat comes into the system
Imma guess A! Idk if it’s 100% correct tho so I’d check that!
Answer: One of the signs a chemical reaction is taking place is the presence of bubbles. :)
Answer:
The frictional force needed to overcome the cart is 4.83N
Explanation:
The frictional force can be obtained using the following formula:

where
is the coefficient of friction = 0.02
R = Normal reaction of the load =
=
= 
Now that we have the necessary parameters that we can place into the equation, we can now go ahead and make our substitutions, to get the value of F.

F = 4.83 N
Hence, the frictional force needed to overcome the cart is 4.83N