Question
Physics Question on laws of motion
A block of mass 2 kg is placed on the floor. The coefficient of static friction is 0.4. If a force of 2.8 N is applied on the block parallel to the floor, the force of friction between the block and the floor is (g = 10 m s)
A
2.8 N
B
2 N
C
8 N
D
Zero
Answer
2.8 N
Explanation
Solution
As f = ?mg = 0.4 ? 2 ? 10 = 8 N. The applied force of 2.8 N is less than f (= 8 N) and as such the block does not move. When the block is at rest, frictional force = applied force = 2.8 N