Answer:
0.002833 sec
Explanation:
Speed of light in vacuum is 
Given distance = 850 km = 850×1000=850000 m
We have to calculate the time that light take to travel the distance 850 km
Time 
So the time taken by light to travel 850 km is 0.002833 sec
Force moves the object but if the same anyone force is applied to both sides then it doesn’t move
I believe it would be 1.6 East
Answer:
I think is Number 2
The rate at which calcium chloride is equal to the rate at which sodium chloride is produced.
Let me know if I'm wrong.
Answer:

Explanation:
Given that,
Mass of a boy is 78 kg
Mass of a girl is 65 kg
We need to find the force of gravitational attraction between them if they are 2 m away.
The formula for the gravitational force is given by :

So, the force between them is
.