Radius of Earth is given as

now here the height from the surface of earth is same as that of radius

now here the acceleration due to gravity at this height is given as



now the force of gravity on the given object will be




<em>so the force of gravity on it is 1.225 N</em>
As we know that block of steel is continue to be in moving state
so here the friction must be kinetic friction between two surface
so we know that formula of kinetic friction must be

now we have


now from the above equation we have


So here we need atleast 14.25 N force to continue sliding the box now as per given options all forces which are less than 14.25 N is not correct
Hence correct answer must be 18.0 N
<u>D) 18.0 N</u>
Answer:
U = 4.39 J
Explanation:
Electric field energy stored in the medium or vacuum is given as

here we know that

E = 81.1 V/m
V = volume



now from above formula we have


Answer:
991.67 miles per day
Explanation:
Since it travels 2975 miles per day, distance traveled in a day =2975/3=991.67 miles