Answer:closed systems
Explanation:
A closed system is one in which matter does not enter or leave the system but there is exchange of energy between the system and its environment. In a closed system, the principle of energy conservation applies. The principle of energy conservation states that energy can neither be created nor destroyed but is converted from one form to another. An example of a closed system is a reaction vessel whose lid is closed.
Answer:
50 N
Explanation:
Since the refrigerator doesn’t move, that means the force of friction equals the amount of force the child exerts on the fridge. If the friction force were greater than the force by the child, the fridge would start accelerating towards the child. If it were less than the force the child exerted, the fridge would start accelerating away from the child. Therefore, the net force must be 0, in this case, the friction force is equal to the force the child exerted, for it to stay at rest (as Newton’s First Law stated).
I hope this helps! :)
Answer:
6480 km
Explanation:
The speed of the object is
v = 7500 cm/sec
We need to convert centimetres into kilometers and seconds into days. We have:


Using these conversion factors, we find:

Yo sup??
we should know that
work done=force*displacement
W=F.s
F=10 N
s=8 m
therefore
W=10*8
=80 N
Hope this helps.