Answer:
Answer: B. 49 N
Explanation:
Friction Force
When an object is at rest on a rough surface, it encounters a friction force that opposes motion.
The friction force when an object is moving on a horizontal surface is calculated by:
[tex]Fr=\mu_k N[/tex]
Where [tex]\mu_k[/tex] is the coefficient of static friction and N is the normal force.
If no forces other then the weight and the normal are acting upon the y-direction, then the weight and the normal are equal in magnitude:
N = W = m.g
Thus, the friction force is:
[tex]Fr=\mu_k W[/tex]
We are given the coefficient of static friction [tex]\mu_k=0.5[/tex] and the mass of the object m=10 Kg. The minimum force needed to make it start moving is the maximum friction force:
Fr=0.5*10*9.8
Fr = 49 N
Answer: B. 49 N
